I used to have a set of Eichbach Pro-Kit and had the same problem too: Right-rear being a bit higher and left-front (driver side) being a bit lower. The whole car looked tilted to the driver's side. It was driving me crazy too. I don't think it's the problem with alignment. Correct me if I am wrong but actually I think it will cause alignment problem? Anyway I switched to Skunk 2 and Konis and have adjusted them so that all 4 corners sit at the same hight with even finger/fender gap all around even down to 1/16 of an inch. I highly recommend coilovers.