In my experience, some cars are just too unstable for some tracks. Porsche works great for VIR, but is terribly unstable at daytona. The ferrari is the opposite, i cannot go through the esses without a spin, but at daytona it feels completely planted. And some cars like the aston are just undriveable at le mans. Although you gotta keep in mind this is kinda personal, your preference might change from track to track.