Never mind the colour, the spec or finding those perfect 20in alloys, now there’s also the small matter of terrifying acronyms: ULEZ (for ultra low emissions zone) and CAZ (clean air zone). These shouldn’t be confused with any congestion charge.

Whether we like it or not, having a car with a petrol or diesel engine that complies with air-quality regulations is becoming a must. These zones already exist in London (costing £12.50) and Birmingham (£8) and are soon to come to at least a dozen more major cities, including Derby, Manchester and Newcastle upon Tyne.

Get caught by the camera in the wrong car and there’s a £120 fine, so you need to know whether you have a Euro 4 petrol (usually from January 2006) or a Euro 6 diesel (usually from September 2015). However, you can’t trust the advertisement or seller when it comes to ULEZ compliance. The only places are official websites, such as urbanaccessregulations.eu, which covers the whole of Europe. Let’s take a look at the best used cars that remain on the right side of these zones: