I know this may have been mentioned elsewhere but it's worth reinforcing for everyone methinks: The recent update to the physics of, for example, the FR Junior means any old set ups you have are useless and in my experience utterly horrible (negative rear toe anyone?). Things to note: (1) if you have old set ups they will LOAD BY DEFAULT - so you will be using them if you don't check; (2) it appears that the old set up files don't map to the new (???) so you may get some odd things happen (negative rear toe or toe out in my case which I doubt I had before - makes the car oversteer horribly); (3) the game loads the last used set up so if you choose the new default set up once it will then load that as your set up from then on. I hadn't realised I was using an old FRJ set up at Sachsenring and the car was awful to handle. I persisted with it and managed to win against AI at 108 (high for me!) but it was really hard work keeping it in a straight line on exit. A similar experience with the FRJ today at Brands made me look at the set up - and there it was - an old one with negative rear toe, low tire pressures (much lower than new default) etc etc. Switched to the new default set up and it was MUCH better. So - clean out your old set ups!!
I loaded my usual Merc AMG setup and it handled like a dog, wasn't until later I realised I had massive rear toe-in, the damn thing wouldn't turn in! As I've learned more about setups I tend to scrap them and start fresh anyway