You car is fine as is, Its very clean and I wouldn't ruin it with a bunch of crap, IF it were mine...
Debadge the 328 from the rear
Tint, ( I prefer dark so personally would go with 15% all around)
Bmw Performance Exhaust
and be done with it...id take that M fast sticker off the side too, looks lame and out of place.
This about sums it up start at 1.25