@Sloppy Shades I think you're wrong. It doesn't matter if you leveled up your car, the BoP will put it as if it were stock.
On the lightest car being baster round corners, yes, in principle. But if it's 1800mm wide and a heavier car is 2100mm wide, that advantage goes away. Same could be said for hight. If it's a ligher car but the center of gravity is higher than on a heavier car, it won't drive around corners faster (fake numbers, they only serve to make a point).
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BoP is kinda working in Gr.3 cars but Gr.4 is all over the place. Mixing FF with AWD with FR and MR and balancing them all out so they're competitive is hard.
But today I discovered that the M6, for instance, was great to do qualifying laps (got rank 1 at Lake Maggiore) but when I went to race with it it was a mess. The tire wear, even with TCS 2 just made the car slower after 4/5 laps. And I mean a lot slower, 0.5 - 1 sec a lap slower than a Beetle or Porsche, when in qualifying it was the faster car.
Unfortunately I signed for BMW just before I discovered this so I'll be racing BMWs with tire wear and I know I'll finish the races a lot slower than my qualifying or my opening laps. I don't know if this happens with other Gr.3 cars but from what I've tested, the M6 was the worse dealing with tire wear.