Well,since the M is almost perfect...
No wheels, I think the 19's look perfect
Exhaust.. Maybe, but the stock sounds perfect,not to much
Interior? nothing much to do there
Exterior? Reflectors
I suggest you go for a Brembo Brake kit.
The couple of thousand bucks will be invested
If you have money left, buy a really nice gift for the wife/gf and enjoy the thankyousex ?