See this thread on a DIY fix, or perhaps print it out and take it to your service centre
:
http://www.mini2.com/forum/showthrea...&threadid=2744
My seat is currently at the mildly annoying stage. I rarely hear it and when I do, adjusting the seat up and down, back and forth seems to fix it which implies, to my non-mechanical mind, a lubrication problem. Perhaps I'll try sticking some lube under there without resorting to full removal of the seat as mentioned above. I haven't asked my dealer to do anything about it just yet (I am pleased that the last attempt at getting the trim to stay on the back of the driver's seat has worked so far).
My Saturn does the same thing and my Saturn dealer fixed it, mostly, by lubing the rails; it still squeaks once in a while (about like my MINI does now). They relube it every time I bring 'er in for an oil change.
Harry