Great tip Steve,
but I think what the issue he is wanting to address is the character line that wraps around the fender at the top. If he is not confident in his skills he may be apprehensive about sanding the flat styrene to match the kit fender.
BTW, Thanks for sharing 'cause I want to widen a set of rear fenders for an upcoming '70 Chevy project!
Much like your shop truck from a couple of years ago!