The factory original upper engine mount (passenger side of engine) is a hydraulic unit that tends to fail over time. If you see a black mess under the upper engine mount, the fluid has leaked out and it has failed.
The factory original engine mounts uses rubber in order to isolate the Noise Vibration and Harshness (NVH) from the cabin. The upgraded engine mounts uses harder compound than rubber in order to limit engine movement allowing more immediate transfer of power to the axles for improved acceleration. These harder compounds also transmit more NMH into the cabin requiring a tradeoff between comfort vs. performance. Select the replacement based on your priorities.
http://www.minimania.com/Mini_Cooper...lication_Guide

 

Nobody is parting out an R56?