I need two rear fenders for a teardrop Im building, I am running 21 in. spoke tires and rims. what I need is at least 7in. at the top of fender[coming straight out from body. I think I can get away with coupe rear, my question is : is a 30/31 coupe fender wider at the top than a 28/29 sedan fender? these fenders will need to be modified [flattened against body] to fit correctly. what model a fenders will work for me thanks, Bruce