I borrowed someones dooley pickup and chipped the top of the wheel well. They said I could repair it myself if I wanted.

My question is can I just use body filler to fill in the chips, do I need to use fiberglass resin, or do I need to use gel coat like boats use? Anyway who is familiar with fiberglass repair I would welcome the help.

I know this may be off topic, but I've searched on the web and found how to repair a boat... but not a fiberglass part on a car.

Brian