Did the second to last racing series in the career over the weekend. Decided to race the Touring cars, with a Volvo of course. (I mean, I had to, I'm from Sweden after all). Right off the bat I bought the diff and lowered the Acceleration setting, to reduce wheelspin out of corners. Lowered the brake pressure, easier to balance when you don't use ABS.
The thing was, it had incredible amounts of mid-corner oversteer. Just rolling through a corner, without any throttle or brakes applies, it would just slowly start to oversteer. The first race in the series was around Indianapolis, which proved to be a real pain. Cornering a twitchy Volvo at 150 mph is not easy, and it's certainly not fun.
Restarted the race to access the tuning, because I just couldn't stay out of the wall. And just like OP describes, any change I made to the car (softer rear spring rate, roll bars, damping and bumping, and lowered front downforce) just made it more twitchy. I was terribly confused.
After half an hour of trial and error I decided to just put the car back to the stock settings and try to run the race. It required extremely smooth steering inputs, and very careful use of the throttle. At the penultimate lap I got some oversteer, over corrected and hit the wall at a slight angle. This just ruined my brakes and the front aero, so I kept at it. To my great surprise, this crash solved all my problems! The car was now perfectly balanced, and could be thrown around the corners flat out. Despite losing top speed drastically I still cut a second from my best lap time.
Next race, I only adjusted the Aero. Minimum front downforce, maximum rear. It did the trick pretty well. In fast corners it under steered slightly, but it wasn't an issue. In slower corners the rear wing didn't produce enough downforce, leading to the same twitchy oversteer.
Conclusion: the only working setting is the Aero. Unfortunately, it doesn't work very well.
