Here's my S988 - Border MR2 tune fit, this was built purely for a high LB position on the MR2 manufacturer race but it is a seriously quick S class car in its own right despite being 10 PI points from the top of the class.. I have my highest LB positions in the game by miles on these races...
Current LB positions and times for the MR2 races (S-Class LB HL Pos)
Maple Valley Shrt Rev - 64th - 3:54.578 Fastest Lap - 37.592 (1247)
Suzuka East - 50th - 4:06.896 Fastest Lap - 47.750 (2222)
Tsukuba Short - 59th - 4:52.331 Fastest Lap - 40.685 (3692)
Build - All Race parts, Max width std size Avon Race tyres, Full Aero, Full WR, Volk TE37 Wheels
StatsSpeed - 6.7 2,269lbs 0-60 3.478s
Accel - 7.7 486bhp @ 7000rpm 0-100 6.596s
Brake - 6.3 430lb/ft @3500rpm G's @ 60mph - 1.18
Hand - 6.0 Top Speed - 189.8mph G's @ 120mph - 1.22
Toon (all front / rear unless stated)
Tyres - 28/29
Gears - FD - 3.30 - 1st - 2.89 \ 1.99 \ 1.51 \ 1.20 \ 1.00 \ 0.85 - 6th
Camber -1.0 / -0.8
Toe - -0.1 / -.0.3
Caster - std - 5.0
ARB's - 20.56 / 13.71
Springs - 308.0 / 462.1
Ride - 3.9 / 3.9
Rbound - 6.6 / 9.9
Bump - 3.3 / 5.0
Aero - Max - 125 / 150
Brakes - 55% Front 110% Pressure
Diff - Acc 40 / 25 Decel
To be honest I really don't know how this car is so fast, I did use traction control with this car as it will spin its rear tyres if you are even a fraction of a second too early applying the throtle... I noticed though on my friends LB that Blooze is about 8-10 seconds behind me on each race in an S987 Border MR2 and didn't use traction control, I have to say that I probably wouldn't have made it round the first lap without it.

Maybe its the gearing as the acceleration this car has is unbeliveable it just keeps going all the way up to 170+ and even with traction control it will still swap ends if your not gentle with the throttle in the slower corners.. Saying that though it does corner really well, turn in is sharp and as long as you are gentle with the throttle the back end really sticks to the road..
Im not sure how well it would adapt to a C-class buld, the rear toe angle would probably be the first change as it is quite high on this car to help keep the back end stable with all the power..