How to shop for an unusual car

Image courtesy of Wikipedia Commons

I find that car advertiser web sites are pretty well-geared towards finding a blue Honda Accord, but not so great if you’re trying to find a pink Borgward Isabella. Which probably makes sense from the point of view of the web site owners, but can be somewhat irritating if you’ve got your heart set on a particular car but don’t want to sit every morning looking at fifteen “no results found” pages.

What I really want is to set up some searches and then wait for an email saying a car’s turned up, and here’s how I go about doing that. I’m going to group these tips by type of solution – please bear in mind that this is going to be heavily skewed to North America, although with a bit of tinkering you can easily apply these techniques to searches in other places.



eBay’s an easy one, so let’s do it first. Once you’ve searched for the car you want, there’s a button at the top saying “Follow this search”. If you then visit your My eBay page, you can turn on email notifications for that search. One tip: the checkboxes for options will filter based on the current search results. So if you want a purple Gilbern Invader you might have to first search for any purple car, and then narrow your results to the exact make and model. Although frankly if that’s what you’re looking for you might be better trying to buy some purple paint, a bunch of fibreglass and a rusty MG.


Much like eBay, Autotrader lets you save searches and have it email you when new cars turn up. You have to create an account, but once you’ve done that it’s pretty easy to use.


This one is a bit of a nuisance but I did come up with some sort of a solution. I wrote a whole blog post about it. Off you go and read that.

Classified ad sites

After a lot of digging around, these are the only sites that I now bother searching (in approximate order of best to worst):

These sites are all geared toward you searching every day for new results. But we can change that! All you need is a free account on

For each of these sites, here’s the process to follow.

1. Search for the car you want.

 2. Tweak the search to be exactly right. 

Sometimes the user interface allows you to get the exact search you want but, if it doesn’t, don’t despair. You can start to look at the URLs that the search generates. These URLs contain the set of parameters that are being passed to the search engine, usually in the form “parameter=value” and separated by ampersands (&). For example, I gleaned that you can search for green cars just by adding &clrId=27128 to the URL. Don’t like the dollar ranges they suggest you want to filter by? Look in the URL – more than likely you’ll see something like prMx=6000 which you can just edit.

Screenshot 2014-01-13 14.09.39

Sometimes the clever filters on these sites stop you from filtering results when nothing’s going to be displayed – you can get around this by expanding the search to a larger area or larger selection of models, and then contracting it again (as I mentioned in the eBay item above).

Another URL trick – when you narrow down a search by type of car, Yahoo autos doesn’t actually change the URL. But you can add two parameters manually to the URL to do this – as far as I can see it’s the make and the model with spaces replaced by underscores. So something like make=bmw&model=3_series. I only know this because they used to put those in the URL, and they still seem to work.

Make sure that the maximum number of pages are being displayed – as we’re going to monitor this page for changes, we don’t want new cars to suddenly appear on page two.

Once you have a URL you like the look of, try it in a different web browser (or a private browsing window). This stops the site from using cookies it’s stored, and allows you to see how ChangeDetection will see the page.

3. Monitor the page on ChangeDetection.

Once you’ve got a URL you’re happy monitoring, head over to and click “monitor a page”. Put that full URL into the box and click “next”.


ChangeDetection now has a few extra options to tweak:

  • only send if sizeable change” – I always check this. They’re pretty vague about what it does, but in my experience a new car being listed counts as a sizeable change.
  • only send if text added/removed” – I always check this and select “added”. ChangeDetection is a little finicky with car sites, just because the removal of a 2004 Bentley Continental and the addition of a 2008 one is often seen by ChangeDetection as only the changing of “2004” to “2008”. But either way this counts as text added, so I check this.
  • Only send alert if added text contains x” – you’ll quite regularly get spurious alerts just because advertisements changed on the page, and you can use this option to avoid that. If your search is generally returning no cars at all, just put something like the colour or make of the car you’re after in there. When a car finally appears for sale, the addition to the page is bound to contain the colour of it, and the change detection is much less likely be triggered by advertisements. However… if your search is often returning several cars, don’t use this trick – as I mentioned above, the removal of a 2000 green car and addition of a 2005 one will not be regarded by ChangeDetection as involving the addition of the word “green”.

Get all these set up and, hopefully, you can sit back and wait for cars to appear. It’s not a fail-safe system – sometimes sites change the way they work, and sometimes you’ll get email alerts just because advertisements have appeared or changed. So every so often you ought to go to ChangeDetection and just click on the URLs manually to make sure they’re all working and you’re seeing the results correctly. But it sure beats going to the same sites every day.

Hope this has been some use – if you’ve got your own ideas, please feel free to share them in comments.

Renaming “Christmas” – next steps


As a non-religious person, I applaud the renaming of various things which once had religious significance. Until last year, “Christmas” in my house involved singing hymns, praying, nailing ourselves to crosses and drinking the blood of bats.  Now, with the invention of the new “holiday yuletide snow fun” period, the event has been completely transformed. We buy a tree, give each other gifts – and this year we didn’t even sacrifice anyone!

I’m equally pleased about the abandoning of the archaic term “AD” (“Anno Domini” – in the year of our Lord) in favour of “CE” (“Common Era”). Previously, every time I wrote down the date I was caught up in a terrible misery over the death of Jesus, the son whom I doubt existed of a god I don’t believe in. As I write dates quite regularly for my job, this was causing me a lot of anguish and I’m very pleased it’s being painstakingly stamped out.

My only complaint is that these changes don’t go far enough. The next things to approach are:

  • The word “enthusiast“, as I’m sure you know, means a person possessed by a god. This is out of touch with modern reality. We should use “fan” instead.
  • The term “OMG” currently stands for “oh my god”. Do we all live in the fourth century now? Let’s stop this nonsense and make it stand for “oh my goodness” instead.
  • Somehow the term “milky way” and its Greek equivalent, “galaxy“, continue to see regular use. We need to stamp this out – although we can’t be sure of exactly where the galaxy came from, we can be confident that it did not come from breast milk sprayed into the sky after Zeus’ baby son woke up during feeding. I recommend we use “distinct universe area”.
  • I don’t believe in the Norse god of strength, Thor, and every Thursday this riles me up into a frenzy. I propose we rename “Thursday” to “Beyonceday” to reflect more current thinking.

These are quite common terms, so making the necessary changes will no doubt take a while. Rewriting the history books will probably be the most time-consuming part, but I think we can all agree that it will be a useful investment.

How to monitor lots of Craigslist sites at once

If you’ve spent much time trying to search multiple Craigslist sites at once, you’ll know that you can’t do it on Craigslist itself and, for some reason, Craigslist habitually shut down other sites that are set up with that intent. One thing you can do that’s perfectly fine with Craigslist is set up RSS feeds to track your favourite searches – however, it’s rather laborious doing this for every single Craigslist site you want to track. Well, I found a (slightly) quicker way of doing it. Perhaps some time I’ll write a web site to do this, but for the moment it’s manual.

To do this you will need:

  • A text editor
  • Some patience
  • An RSS reader which can import OPML files. I’m going to use Feedly here, although I’d recommend using a mobile app that isn’t Feedly’s own horrible one – I use gReader

First you need to get a list of the prefixes of the Craigslist sites you want to search (e.g. This is the most laborious part. They’re listed state-by-state. For each of the states you’re after, go to the equivalent of (change the state prefix at the end). The easiest way to get the prefixes out is to view the page source in your web browser, then copy and paste the list into a text editor and do some search-and-replace and some manual editing. Hopefully you can end up with a list something like this:

You’re probably also a bit bored. Fortunately, the next parts are less repetitive. Now you need to go to one Craigslist local site and search for whatever it is you’re actually after. Copy and paste the URL into a text editor. It should look something like:

You need to turn this into an RSS URL – ou can do this by adding “&format=rss” to the end of it. So you’ll end up with:

You now need to make a search-specific URL for every single one of the specific sites. I just did this by doing a search and replace on my site list and replacing “.org” with “.org/search/allmysearchstuff“.

If you’re carefully following my instructions, you should now be in posession of a list that looks like this:

Excellent. if you only have a few of these you can add them to Feedly one-by-one, but if you have a lot then it’s much easier to do it via an OPML feed import file. Go to the feedshow OPML generator and just paste in the list of RSS links you have above. Click “Create OPML”. Hopefully your web browser will show you an XML file. Save this somewhere.

Now, off to Feedly. Under “My Feedly”, click “Organize”. You should see an “Import OPML” button – click on it, and import the OPML file you created above. Some time shall pass and then… tada! You now have RSS feeds to all the Craigslist sites you were monitoring. Depending on which app you’re using to consume the Feedly feeds, you should be able to get alerts on your phone when new listings appear.

There. Don’t say I’m not good to you.