WD-40 first followed with mr cleans magic eraser..
on signs...just the eraser after cleaning with dawn and water..
always works for me.
I tried simple green and found on some cases it will dull or remove paint.

Paddy
Wanted. Billups, Ride with Rose, Har-V, LORECO, STANOCOLA, Pan Am (early), Hurricane, Evangeline, Canal, Gulf Coast, oil companies.