Thanks guys
I guess it's been a while since I wrote an update. Admittedly the testing had a little summer break (I focused on my RWD car), and recently I picked testing back up again.
For the most recent test I rebuilt the shocks (it was overdue), and I decided to overhaul the whole setup too, with new pistons, oil and springs. The car was tested on clay last weekend, and the progress is noticable: The car is much more stable over bumps and the front end is more predictable. Also, I cut about half of the wing's gurney off, which loosens the rear a touch in a smooth way and makes the car jump better, particularly in windy conditions.
In upcoming tests I hope to be able to test a new suspension and driveshaft system for the front end. It will use industry standard rear wheels like the current setup, but it uses different driveshafts and geometry from what I've used up to now.