I'm not a guru but can speak from experience - had 2 minis over
a period of 3 yrs. Biggest issue is structural rust/ decay - both
my cars had it well hidden until things started falling off.
Mechanicals are simple, but space is tight for DIY. Was able to fix
simple things myself but larger jobs require careful selection of
mechanic - I got ripped off by a few of the "specialist mechanics".
The reason why I got rid of my last Mini was because the mechanic
kept discouraging me from fixing it and telling me to buy his
customer's car which was up for sale instead.....didn't like being
held ransom like that.
They're not very fast, awful standard brakes, bouncy ride. You
either love them or hate them. I still love them and look forward
to owing one again, maybe as a fun weekend car.