Ford's legendary Sierra and Escort RS Cosworths conquered worldwide motorsport, while changing the face of high-performance road cars forever. With turbocharged two-litre engines producing over 200bhp, these four-seater everyday saloons could keep pace with supercars - and their 500bhp-plus circuit-racing counterparts overwhelmed everything in sight. Even now, Sierra and Escort RS Cosworths are in touch with modern machinery, making them as desirable to keen drivers as they are to classic collectors. The RS500 in particular is a rare beast, commanding prices normally befitting upmarket brands. Sadly, many Cosworths were stolen, abused, crashed, copied, neglected, and modified, which makes buying one today a task that's fraught with risk. To help the would-be RS Cosworth owner, this quick-reference guide acts as a handy pocket-sized companion during the purchasing process. It aims to help buyers select the best car, pay the right price, and avoid the potential pitfalls. Written by a motoring journalist and long-term Cosworth enthusiast, this one-stop package of great advice includes at-a-glance tips, illustrated in-depth inspection guidance, specifications, notes on modifications, real-world cost considerations, and even checks to help spot a fake.