Bought an enclosed trailer that previously had several large vinyl graphics on it . They had been removed for about 3 years , but they never got the adhesive off when they peeled the graphics . Now the sun has baked on it for 3 years , and I cant get it off. I have tried 3M decal adhesive remover , goo Gone , and the rubber eraser wheel and nothing touches it . I need help on this one ... Thanks in advance