[enkeivette]

I would attribute the fishtailing more so to having crappy tires. First, upgrade those.

I would attribute the last 6 seconds of your fishtailing to your lack of desire to let off the throttle.

As far as suspension, lower, stiffer, bilsteins or konis. :judge Contrary to what you might think, a stiffer spring in the rear made my car far less prone to fishtailing. Prob has to do with keeping the tire in place and more tread in contact with the road.