Board Thread:Game Discussion/@comment-27526307-20160102070137/@comment-26249703-20160102111253

For Class:

F - Doesn't exist? Let me know which car otherwise

P - Production

R - Race

S - Supercar

These aren't very telling, as there is a very wide variety of cars and 3 classes is not really enough to differentiate them. Also, The class associated with each car doesn't always make sense. For example: the Chevrolet '69 Stingray 427 is in Class R, but the Aston Martin Vantage GTE is in Class P.

For FR, M4... As Master Racer said, this correspond to the Drivetrain layout:

First Inital: Powertrain Position (F=Front, M=Mid, R=Rear)

Second Initial: Driven Wheels (F=Front, R=Rear, 4=All)

A few have been considered by users to be wrong, but we have no power over that. Most often, it's to do with Powertrain placement as Mid does not account for Front-Mid or Rear-Mid, meaning they're sometimes labelled as F/M/R when comparable vehicles would have different initials.