I thought I liked the Muscle Car spec too, sadly after testing I can now confirm that the whole class is now ridiculously upfucked. I tried 450PP too as it seemed some were gravitating towards that number but sadly that's just as bad, I know the cars are supposed to be different but it seems like there's no clear way to even halfway balance the class now like it was before the change.
Before I think most cars were fairly equal at 535PP with a couple that were slightly better than the rest but at least "the rest" were pretty well balanced, now it seems like no matter what you go by (PP or power / weight) you're lucky to find even a pair of cars that are evenly matched.
Heck even trying to match all 3 together doesn't really help, some cars just have higher PP and suffer a power and / or weight penalty that pretty much renders them useless, I seem to remember before that was also a viable option even if we couldn't set the room by all 3 numbers.
The problem I'm finding with running power / weight set ups is that I'm finding the odd car with overly high PP which usually translates to it being significantly better than the others. Case in point being the Luxury Sedans class, previously just on PP I think it favoured the M5 and using power / weight has the same effect.. the M5 just handles tons better than the rest, I was testing at 502hp / 1610kg and the PPs ranged from about 470-520.
Interestingly when running the same hp / kg the M5 was at 520PP and the Lexus ISF was about 480PP, the Lexus handled well enough through the corners but didn't quite have the power (or gearing?) to keep up with the the BMW. The Chrysler 300C was 513PP and just sucked balls in every aspect compared to the M5 yet was very close to in PP.
It's like the new values they've assigned to cars are completely random with no bearing on how the car handles or performs.
I'm fairly sure Ferraris, Lambos, GT300 and GT500 are still usable, Nascar and Karts too as there's really not a lot of choice of vehicles there
. There might be a couple of other potential classes, I'm almost thinking that grouping by year may be a good thing as I've got a selection of 80s / 90s cars specced for 400hp / 1200kg that all seem to be around the 440PP mark to test.