Trust me the MINI paint is harder than the MR2. BMW paint is the hardest paint you can have to polish.
If you want to know how to polish your car properly visit
Detailing World they will recommend the Porter Cable random orbit polisher as it's hard to do damage with a random orbit. Trouble is they need to be imported from America (that's what I did).
Chips away rarely give good result on paint chips and it's better off going to a bodyshop TBH. Plenty of threads on here and Detailing World about them.