This works for me:
SR: 12.5/14
RH: 83/87
SB: 5/6
SR: 4/6
C: 2.2/1.0
T: 0/0
S: 5/5
BB: 12/10
(Add a wing and max the downforce front and rear.)
LSDI: 10
LSDA: 40
LSDD: 25
ASM: 0/0
TCM: 5
721 HP, all drivetrain, chassis, and lightening mods. Don't forget R2, R3, and R4 tires for the Mercedes one-make events. You'll win the Silver Arrow event easily with this setup, which gets you the CLK Touring Car, which you can use to repeatedly B-Spec spam the German Touring Car Meisterschaft event (European Events) and sell the prize car again and again for huge bucks.
I use the old "Tranny Trick" from GT3 to set up my gears: Run the final drive to the highest (5.000), then slide Autoset full right, then slide it back full left to 1. Now set the final drive to the correct one for each track. This gives you an extremely close set of gears. (I think my Nurburgring final drive was 4.00.)