Used car buying guide: Ford Escort RS Cosworth

With its pop-out rear windows and standard-fit sunroof, the latter is the most prevalent today, with prices starting in the mid-£30,000s for tatty high-milers and rising to around £60,000 for dry-stored examples with reams of receipts and unchanged powertrains.

Untouched Motorsport cars are harder to source, having mostly been modified for use in, erm, motorsport, but they do crop up occasionally – usually finished in Diamond White and with an £80,000-plus price tag.

The YB motor isn’t rapid by modern standards but is highly tunable. The smaller turbo can handle only about 300bhp, though, so speed freaks often upgrade to the bigger one. Like many cult classics, it’s the factory-spec cars that command big bucks, so avoid any with aftermarket bodykits and energy drink logos.

How to get one in your garage

An expert’s view

James Wills, Auto Dynamix: “This is the ultimate cult car. The one we all wanted. The poster on the wall. Low-mileage examples can go for £80,000 and, once one sells to a collector for that sort of money, it commands the price for all the others. That’s why prices rocketed in just a few years. Look at Renault 5 Turbos, Vauxhall Novas and the like: they have also risen to mind-boggling figures for pristine examples.”

Buyer beware...

â–  Engine: Dripping oil will usually be coming from the cam cover, so check the side of the block and the cambelt for signs of a slick. Some smoke under acceleration is forgivable, but excessive puffing at idle could give cause for concern. Any modifications carried out unprofessionally definitely will.

â–  Steering, suspension: A radically lowered front end is detrimental to the Cossie’s famed handling characteristics and can cause driveshaft issues. Similarly, polybushes and adjustable rear beams improve performance on track but don’t make for a fun road experience.

â–  Bodywork: Panels are generally solid, but look for corrosion at the base of the rear windscreen, around the fuel filler cap, below the battery, at the front of the floor pans and behind the side skirts.

â–  Interior: Headlinings wear over time and can fall down, while leather seats will start to look tired, depending on mileage. The electroluminescent gauge cluster starts to look mouldy as panels fail but is easily replaceable. Enthusiasts bemoan ‘RS Tax’, which has driven the price of hard-to-find clips and trim pieces into the hundreds of pounds.

â–  Brakes: Modified cars with more than 300bhp need beefier brakes, so ensure these are present and correct. Otherwise, the system is reliable. Check around the brake pump for heat damage caused by the lack of a turbo shield.