Considering a used Mini Cooper S, suggestions...
 

Good day all, first post here.

Due to the sudden need to put down some money on a house, I'm selling my '06 M3 and am considering a used Mini S (manual) as a replacement, and I have 2 basic questions I was hoping you could help with:

1) What is the difference between the '06 and '07, I noted one is M53 while the other is M56.

2) What parts are the most common failure items that I should most carefully inspect.

Thanks!