The Z Broz springs really took the car to the next level. Got rid of a lot of washboard and chop in the dunes. It does take some time to fine tune the set up (preload, cross overs, HS/LS compression, rebound) but with the great help from Harley at FastLab it went well. My car rides great now and is noticeably better than a stock X3. I had the springs powder coated through FastLab with the matching teal, they worked with me to get the springs done before a dune trip and i picked them up from Collin after hours. FastLab helps the customer tremendously.