Cosworth enthusiasts are walking on air these days. Well, the ones who actually own Cosworths, anyway. The original blue collar supercar, the road-racer for the everyman, the OG, the GOAT… the whole point of this car was to provide ridiculous performance at a not-ridiculous price point; sure, its real purpose on paper was to homologate the Sierra for Group A competition, and of course that’s a role it fulfilled with alacrity, but there’s something owners recall with just as much misty-eyed fondness as all that motorsport prowess, and that’s the fact that ordinary people could wander into a Ford showroom, slap down a wad of twenties and drive home in something unbelievably fast. For a time, it was one of the most stolen cars in the UK, and they became…