For the C5R, to decrease front tire wear decrease front downforce. You can also run harder tires on the front than on the rear. It matters not how many laps you get between pit stops as long as you can run longer on your tires than the AI, with similar lap times. If you can run
twice as far as the AI between pit stops, then you can win in a slower car. (See my thread on running the Rome Enduro in an MR-S.)
The RGT
feels faster, but driven conservatively, the CTR is actually blindingly fast. Like 2 seconds a lap faster than the RGT. One of the things to remember is that with the Porsche/Ruf Rear weight bias, you will get oversteer if you lift off the throttle once you've got weight shifted to the outside of the turn. You can also dial out the understeer by raising the rear of the car. Then you can drive it in a more
conventional manner.
The Esperante is an interesting car. If you try to drive it right out of the box you won't be impressed with it at all. Especially if you bought it rather than won it. Once it is properly set up with the tranny also properly set up, it is quite tame, and very fast.
The Vertigo is simply the fastest thing in the game under 500HP. And faster than much of the competition OVER 500 HP. Still, it has to be set up well. But its light weight makes it fairly gentle on tires, and it's grip is awsome. Test one in arcade mode with a set of T8 tires. You will be pleasantly suprised.
As for the Escudo, without Pike's Peak in the Rally courses, it is kind of overkill. It also handles poorly on road courses.
As for the Lister, I haven't won one yet in THREE different games. I have driven it in GT2, and wasn't taken with it. The Renault ESpace mini van was pretty cool though.
My personal opinion re: the most over-rated car, would be the Toyota Supra modded to over 1000 HP and the Skyline modded to over 1000HP.
Neither of these cars handle or accelerate worth a tinker's damn modded to that level. In the Supra, once you are over 650-700 HP the car will sit and spin its drivewheels on take off, then when you try to put power down in the turns you get uncontrollable oversteer. With the Skyline the understeer gets WORSE. If you set the VCD to try to compensate, you spend a lot of time spinning backwards off the track, provided you can shift quickly enough to stay in the powerband with a Stage 4 turbo. But in a straight line with AWD you can effectively put more HP on the ground for good acceleration.