No problems to me...
Made the championship between Sunday and yesterday.
Maybe because my B-tard is a level 28 now, as I advanced in the B Spec mode until I had the money to buy the Formula GT.
As for setup I've only lowered the car, maxed the wings and that was it.
From race to race I just adjusted the gear ratios.
Pretty easy championship, won every race by miles, except Cote d'Azur where he spun three times and came to first only a couple a laps before the end of the race.
I used hard tires, and swapped once for race, but, has the fuel isn't enough to complete the whole race, except once, that's no problem at all. Usually I can build enough gap to pit with 2/3 of the race and return on front. Then they pit 2-3 laps before the end of the race when the fuel is on the red, but they loose a lot in the last laps with old tires since they are finished.
The trick is change tires and refuel sooner because is more advantageous to use fresh tires then a lighter car.
Look out with changeable weather because in the next race it starts with the same kind of tires he finished the last race...