Don't want to sound fanboyish and I can imagine that the car isn't accurate, but have you refreshed the engine, oil and body in GT Auto?
I have changed the oil, but I did not rebuild the engine or restrengthen the chassis. What I have read so far the Chassis rebuild thing is very buggy/glitchy as well. Some folks did one race with a brand new car without incidents and after that had the option to rebuild the chassis for lots of money. Referring to a new premium here.
So I decided to stay away from that.
I did however installed the strut brace in the chassis/body tuning menu. But the fully tuned R32 still tended to oversteer quite a lot. No poweoversteer but lilftoff oversteer and it was very twitchy under braking. Even after I adjusted the brake balance from 5/5 to 8/5.
Well I don´t know. I was amazed of the feel of other cars though, the 370z for example or the R5 turbo.
But this car stands out for me especially because I know first hand how it should behave.
Well maybe I will give the chassis rebuild thing a chance and see what happens. But I doubt that it will completely change the behaviour of the car.
I think its like with the graphics of the standard cars. Some have been simply copied from previous versions (the Veyron has the same bug as on the psp version. The spoiler retracts faster than the struts that hold it, so it looks like they penetrate the surface) with all the bugs and imperfections.
And some have been worked on to at least try to get them to gt5 levels.
I don´t know. I have driven (or rather had to drive hehe) a couple of other standard cars and they were fine.
Oh, btw its not the tires either as I installed sport medium tires.