If it were me calling the shots, there would be hopefully 2 classes 3 max. I would cut GTLM, but that would probably put the series in a bind financially due to the manufacturer presence putting money in the series. So that's pretty much not gonna happen. With a 3 class system, I would've given all 5 LMP1&2 teams from the ALMS a credit for a DP chassis of their choice. That would've removed the BoP headache. That would be the P class. Some minor and cheap upgrades would be all that's necessary. Keep the GTLM class as is for Le Mans link. GTD cars would have the stock body shape. I'd allow the tube frame cars in it like the grand am RX-8 and Camaro in with the others as long as those cars kept an approved engine that is subject to BoP as well. No aero or major modifications from the stock spec. So no wings, dive planes, wide fenders, or engine swaps (looking at the Z4) for the sake of performance. Of course, safety modifications will be necessary as well as BoP measures. No number panels, colored mirrors, or driver ratings. Now that's a 3 class series that's easy on the team's wallet, easy to follow, and easy to steward.