autotrader.co.uk has a handy feature that tells you how far away a car is from you. The niggle is that it does not tell you where the seller is based.
If, like me, you live on one side of a large city, an as-the-crow-flies journey of 40 miles to the other side of London is considerably less attractive than a 40 mile trip down the A3 to Guildford. For various reasons, you may not be able or want to phone every seller just to ask them where they are before deciding which ones to follow up.
With this in mind, I decided to make use of Google Maps UK to triangulate the location from three or more known locations.
The idea is to use at least three of the post codes below above as your 'home' post code in an Autotrader search. Note down the distance from each one to the car you're interested in and enter it into the corresponding distance field in the second form below.
You should then have three or more circles drawn on a map of the UK. Where all of them intersect is where the car is located, with an accuracy of a few miles.
Presumably, you have a particular car in mind...