Let me check some things, and please help out if you disagree:

1 A stiff rear suspension, would give a vehicle oversteer when applying too much throttle on the exit of a corner. (existing L setup)

2 A soft rear suspension could increase the traction at the rear, so as to get more understeer when getting on the throttle on the exit. (similar to a front drive vehicle, but without the "pulling" effect the turned front wheels have)

This would be very tough to drive, as you would get a lot of grip when backing off (loading the front wheels), but understeer as soon as you try to increase speed.

This seems to me, to point towards a shock change to improve the ride, but to leave the springs alone. Comments?

 

What i notice is especially on the lightning is,You need to be ON the gas to keep it from going around on you.When you let off you will spin it around.