You may need to go to a detailer to have the old paint mechanically buffed off.
Try the "goof-off". It may soften the paint enough for you to rub it out by hand. I like the No. 7 White polishing compound.
2004 E60 530is, Delivered 12/12/03, TiSilver/LGrey, PP, SP,PS, PDC, ACC, FRS, Step, Xenons, clear bra, body colored rear inserts. (Retired, 1983 henna red 320is)
2004 Corvette Z06 Commemorative Edition