yeah, same response for me at ACE.
Don't worry about Bondo. It was my first time Bondo'n too. I just read the instructions, and did what it said to do. Bondo is for leveling out surfaces that have small bumps in it, or for filling VERY SMALL cracks. Not for filling huge cracks of missing metal. That is why I think so many people have problems with Bondo. Here is an example of my noob bondo job... but it worked!
-I cut out all the holes
-Matched the size with some scrap metal (from the hood of a parts car)
-Tack-Welded it in (with a crappy welder)
-Grinded it down with an angle grinder, then DA Sanded it so it was as smooth as I could get it
-did the Bondo Thing
-Sanded, Re-Bondo'd it up, sanded again, and slapped a coat of paint over it. Sorry, but I don't have a pic of the holes after the whole job was complete.
Sorry about the quality of the pics... and they are somewhat dated. That was after like, 2 coats of paint. I ought to get out there and take after pics of all the little minor things I fixed... like the gash where a tree hit the roof... looked like this before...
and this midway
Just need to get me a better after pic...
anway, if I could do it, you can do it! You just have to be patient. If the directions says let it dry for 30 minutes, let it dry for at least 30 minutes!