Purchased my '06 R53 in BRG with 53K miles in January - my first Mini and so far I'm really enjoying the car.

Almost right away I noticed a sharp squeak from the passenger rear when I would hit a bump with the passenger rear wheel. I did some searching and tried lubricating the rear seat brackets and latches but the squeak is still there. Just in case I also lubricated the passenger door latch and hinges - still no joy. Any other ideas?

 

Might be the rear sway bar....

 

^For serious. Take a peek at the bushing on the offending side. Could be overly dry or ripped.

 

Exhaust hanger against the underside of the car will squeak, especially if it's hitting the battery box.

 

I have the same squeak and it's driving me insane. I need a good afternoon to troubleshoot. Seems to be worse in the cold...