In the early 1980s, both BMW and Mercedes-Benz offered big coupes based upon sedan brethren. But to get the performance that matched their looks, before 1985-1986 you needed to look towards the “Grey Market” to get the hotter original specification motors. For the BMW 6-series, that meant the 635CSi jumped from 182 horsepower to 218, with 10 lb.ft more torque, too. But the Mercedes-Benz SEC was the big jump in power, with 27 horsepower more than the 380SEC but a massive 67 lb.ft of torque added. Coupled with lower weight, better headlights and slimmer bumpers, today these Euro editions are still quite popular and highly sought. Today I have two to face off; are either worth the high asking price for the ticket of admission?