I am working on a 1986 Monte Carlo for my friend, There is a crack coming out of the lower marker light that sticks out farther than the rest of the plastic. I filled the crack with plastic repair but I don't know if I should try to build up around the area or sand it down, I know that sanding down will make it thinner so I really don't know what to do at this point. If you guys can point me in the right direction I would appreciate it.