Some tuning advise, i know im not the fastest ......(yet, lol) but thought id share my findings, ground breaking they are not.
I took some time last night to listen to each explination of what each setting does, (yer obvious i know) and i found that if i set the car (for this car/track) for lots of oversteer, and then tweak it away from this until the car is stable, it took me a couple of hours to get a decent setup, but i went from 1.36 laptimes to 1.29 within that time frame.
I can see why people are frustrated with this game, but take my word for it, learn the tuning section, and you set much better lap times. No one can really tell you what there settings actually are because not every setup will suit every player. Just get a exagerated start point (oversteer is best personally) and rain the car in from there.
Hope this helps