I have had a set of Tein SS coilovers installed on my car for the past 2 months or so and have noticed over that past couple of weeks a creaking sound coming from the rear coilovers.

I first noticed it during a period when it was running a couple of days straight and had made the assumption that the noise is worse when they are wet i.e. after going to the carwash. My car is only lowered about 1.5" at the moment and still have stock 17's. It is very noticeable when you slightly lift up the vehicle at the wheel arches on either side and is becoming an annoyance while driving. No sound at all from the front of vehicle. I originally thought that it was the bushes on the Whiteline RSB but found it definitely isn't the problem.

Any ideas?