For starters every German car as of 1996 has water bourne paint,unlike the original Gasurit lead paint used in the past. I suggest using a yellow foam medium cut pad @1200 rpm's with a electronic buffer,ie Makita. If you use a orbital or, porter cable or cyclo , you will in fact be there for days for the first cut,
Wipe the car down with some wax and grease remover on a micro fiber towel, to remove excess swirl marks.
then if you have a random buffer or a cyclo with another yellow pad us a finer compound or swirl remover to remove the left over swirls. wipe that down.
then apply whatever sealer or wax after that with a green,blue or white foam pad.
You will have a perfect finish