What products have you tried? You know, it might be rust? Have you rubbed all the paint off your ride?
Anyway, other things to try depending on what the problem is:
You might try Gel-gloss from Home Depot. A gentle clay bar substitute.
If that doesn't work try No.7 white polishing compound.
You can apply both of the above by hand or with a rotary polishing machine.
If that doesn't work there are some other heavy duty rubbing compounds buy you can leave a whole lot of swirls if you don't have the experience or the right mechanical polishing equipment.
You might have to get a professional detailer to get the junk off.
Also, you might try some bug/tar remover. Use in shade on cool paint.
Try all of the above in a small, inconspicuous area first to check the results before doing your entire ride.
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