Some cars in Forza have two of their trims available, many times it’s a high performance trim next to a semi-racing trim. Take a look at the BMW M3 E92 and the M3 GTS, the two share the same model but not the same body mods, but they absolutely could since M3 GTS aero should be ported over to the normal M3. Or the 2012 Viper GTS, with its track-focused version being the 2016 Viper ACR, both share models and I think the Viper GTS should have ACR aero available as its race aero instead of Forza’s default aero. One example which kind of boggles my mind is the 2015 Jaguar XKR-S GT, which has an identical model to the 2012 XKR-S, but with more openable panels, optional wheel spacers and factory aero that for some reason isn’t adjustable. While I understand that making non-adjustable aero suddenly adjustable would break some tunes, I think the race aero for the XKR-S GT should be changed to be just slightly altered stock aero (do what you’ve done with the Aventador J, it has the best Forza aero I’ve seen since FH1), and the XKR-S should get that altered GT aero as its race aero. There are even more cars which should feature body parts from higher trims, such as the 2002 Acura RSX, the 2015 Lexus RC F, the 1997 Mazda RX-7, or the 2015 Mercedes AMG GT S. The list is really long, but changing this one visual aspect of some cars would simply make them overall better.