Need buffing advice

Well to really eliminate swirls the best way is with a machine. If you don't want to mess anything up, a random orbital buffer is the best route (not a rotary). Then just tape off the trim and go to town. Of course there is buffing technique, pad choice, and compound choice to consider but that really is based on how bad the damage is and how hard/soft the paint is.

try mothers carnuba cleaner was first it worked great for my bro's black gs 300

Get a claybar kit and claybar it, go over it with like scratch x rubbing compound, then wax it. did that to my black g35 that had tons of swirls and scratches and it looked 100 times better.

Best thing to use is a DA polisher, if you don't have that then you might as well do it by hand with generic products. I use a Porter Cable, and Poor Boy's Polish/Compound.

Alex