The last time I did backyard hack bodywork was on a crappy van that I kept as a junk hauler , but it needed an inspection sticker that it couldn't get due to the rot holes . I knocked out the rot , backed up the holes with chicken coop wire , and then slathered the Bondo on . After a few layers were slathered on and knocked down smooth a bit of paint hid the butchery and the all important inspection sticker was granted . The Bondo rot disguise lasted the final few years I had it till the engine died and off to "Pick & Pull" it went