Changed my apex spring there last month for my CS3 but had to go back few times to check on the knocking sound issues on the right side spring. The 3th time i went down and he told me the sound is unavoidable as sometimes it will have the sound. Finally cannot bear with the sound and went back to ask him swop back my stock spring worse case. Instead of proposing some alternative solution like maybe they try to change that particuar right spring and see how to solve that issue, he just readily say okie to change back when i proposed him my solution of swoping back. And i was charged $70 for swopping back of the stock spring. I understand that maybe some ppl changed the spring and have the noise which is unavoidable, but shouldnt the shop tackle on this issue to find alternative solution when they know it's unavoidable. I understand the springs may not be expensive as compare to coilover but it is still after sales service rendered to ppl that is important. I would strongly advise ppl to do some homework before doing anythihg.