I have a 2006 Mini Cooper S with the JCW package. Its has 115000 km's and the automatic transmission when warm revs high and slips into gear when the accelerator is released. The problem has yet to occur in sport mode. I was wondering if anyone had any solutions that may minimize the cost and prevent the purchase of a new or rebuilt transmission. Thanks

 

Replace the trans oil with synthetic Redline auto trans oil. Also replace the filter.
It sounds like the metal particles maybe starting to clog the oil passages in the valve body. It could come down to replacing the valve body in the long run.

 

Moving you to the Gen1 Stock Problems/Issues area. JCW or S its the same transmission.