There is great polish "White Diamond" metal polish it's in silver and white bottle and is the consistency of milk. I also buy two sets of Harbor Freight's imitation lambs wool buffing wheels . Wearing a mask, a long long sleeve shirt and gloves, I wipe the polish on in a 6" area waiting a minute for it to activate wit the aluminum. Then lightly rub the surface with a cloth it quickly turns black, wipe that excess away with a paper towel , using a 4" lambs wool wheel in cordless drill buff it up. Use a 2nd clean wheel and lightly run back over the area and final clean buff with a tee shirt. Windshield frame takes about 15 minutes and four wheels similar to Troy's takes about 2-1/2 to 3 hours. Total material cost is under $25.