I'm at the point of respraying the black stuff back onto the wheel wells. I have two cans on the shelf: Rustoleum and Bondo.
Is one better ? Any other products I should consider ?

This is what I used.... great stuff.

Wuth also makes an excellent rattle can black rubberized spray-on undercoating. May have to purchase it over the net. Of your two, I would go for the Bondo product since they specialize in car products.

Are you going to leave the coating black or paint it body color ? If you want to paint make sure what you use can be painted. If you think you ever want to be able to remove it I think the truck bed coating would be more difficult to remove.

I would suggest you go to the various suppliers and buy one can of each brand, and experiment on something besides your car. They are all different, and act differently. Once dry, some are much softer than others... I know it may cost a few bucks, but you will be happier with your choice...

that bed coating in a can is a comlete waste of time. Throw it out or put it on a yardsale table. I bought a can to see what it was like. Get real undercoating. #m, Wurth and some other make them in a spray bomb that works really well. I use quite a bit of those brands.

http://www.autobodytoolmart.com/3m-underco...81-p-10787.aspx

I was thinking of doing the same thing.
But then I'm going to do a complete paint strip in a couple years.
Would undercoating the fenders make me a whole lot more work in a couple years? I'm only going to drive this car in the summer. Or until my kid steals it and takes it to Stanford.

Plus I thought there was discussion about water getting trapping behind the undercoating.
Or am I just in information overload and thinking of another area?

If you're going to do a complete strip I would leave it be. Getting the undercoating off is a messy PITA. Part of the problem with dealer undercoated cars is they sprayed the undercoating right on top of the hardened glossy paint. There was no way for it to bond. Nowadays the chemicals are better at bonding and iif put on within a day or two of painting it should hold up well. Otherwise a light sanding with 220 grit will help the undercoating to get a mechanical bite

Click to view attachment

Have the sandblasted surface painted with an industrial
paint like they use for heavy equipment

Click to view attachment

Then have it sprayed with kevlar truck bed liner

I lke the European style undercoating it doesn't use tar it's like the stuff they use at the factory, comes in grey or beige.

http://www.proformproducts.com/en/products/detail/?id=22

Interesting. Are their products available through any of the national chains ?

Should have it at local parts stores, we have it at Lordco in Canada, sort of like a Napa down south.

hey Das snow man... Hello from a fellow Canuck just a hop skip and a jump from you