Feeling my Passion's suspension a bit mushy, I thought--what would the NASCAR guys do? I went to NAPA and bought 2 sets of front rubber coil spring "stabilizers," NAPA # 704-1279 ($4.89 each). I turned the install over to a local tire shop. What an improvement! Better cornering, better ride, better dealing with potholes, speed bumps, etc. Is it as good as aftermarket performance springs? I wouldn't know. . .perhaps. . .probably not. But a great, cheap, easy fix. Napa sets for the rear coils are too thick, but the sets for the front work just fine for the smart rear coils. The install raised the smart front end 1/4", the rear 1/2".
I'm a boat guy (own 4--12' to 62') and innovation is the order of the day with those rigs.
Louis