I will try to explain what I've felt when I put my mini in reverse. It's like the engine starts to tremble, somewhat like somethings loose. Only in reverse, this doesn't feel in 1st gear, or 2nd gear. Could be a transmission issue? It's like the engine starts to rattle in reverse. Mi mini has +62K miles. This happens when the engine is cold or hot. Is something I can check to fix this? Thanks a lot in advance!