Slowest car ever round the Top Gear track?!?
The rear shocks on fwd A3s are a bit weak. When I changed mine at ~70k miles there was virtually NO damping left in them (you could move them easily by hand).
Try bouncing the car up and down at the back and see if it continues to bounce when you let go or if it comes to rest quickly.
I'm led to believe the rears are quite an easy DIY job although I haven't done them myself. As I understand it the fronts are a bigger job if you were thinking of doing all 4.
AFAIK it isn't possible to adjust the rear wheel alignment on a fwd A3.
1997 1.8T || AmD Stage 1 || Eibach springs || Bilstein shocks || EBC Brakes - Gone!
2006 Nissan 350z GT