Those cars have terrible handling in real life too. You can't simply have a lot of power in rwd vehicles and not spin your tires like a maniac. :lol:
That is why those cars always have electronic traction control and ESP, ASM and all sort of assists.
But, if you want more traction, increase the "grip" value in TDU PE. That is basically how much grip the tires will provide. TDU standard value is 1000.
Edit: You can also reduce the "Oversteer" value aswell. That makes the rear less loose, but also results in worse cornering ability. TDU standard value is 100.
Edit 2: And i do understand about car physics and setup, not trying to brag or anything, but i've won 2 online championships in Gran Turismo 6, so, i know how a car works, how a suspension works, oversteer and understeer...
Some cars will have poop handling because the 3D model was somewhat bugged, and the rear of the car was way too high, and to bring it down, i had to put a ride height at the rear smaller than 100, which hardly works in TDU, as it understands that the vehicle is scrapping the floor at high speed. Ferrari F12 is one of them.