Cheers Colin. I'm going to Knockers tomorrow, so I will have the car jacked up to put on the track wheels anyway. The noise is only apparent when slowing right down, not at any other time. The last time out an KH, I heard the sound around the 3rd corner, then it never came back again, even afterI came off of the track. It is only recenly it has started again. I'm still under warranty, so I'm not too bothered, just as long as it doesn't come flying off on the track!