Multi-class sports car racing is already incredibly confusing. Many of the cars look the same and are only differentiated by varying tire compounds and engine specs.
It's doubly confusing in America because we have two competing sports car endurance series in the ALMS and Grand Am and they both have different class names. I'm willing to bet that a casual viewer has a brain aneurysm when trying to discern between all the classes. I mean look at all of these: P1, P2, LMPC, DP, GT, GTC, GX.