Does anyone know if I should change both my springs and shocks when I lower my A4 Avant? I was thinking of only the shocks - maybe Eibach or H&R?! Any suggestions??????

I changed to Eibachs without changing the shocks, per Tire Rack's suggestion, but it was a mistake. The lowered car looked great but it porpoised and bottomed. Now I have Bilsteins and the ride is great! I made the same mistake on another car, changing the springs without the shocks, and had the same problem. That time I started over with a matched set of springs and shocks and really saw an improvement.