zeibert undercoating & rust proofing

[doylee4693]

I bought my car with undercoating already on it and it was last done in 2007 and is looking pretty patchy.I myself am not a big fan of the undercoating but I dont have the time to sit and scrape it all off so im going to get the undercoating "touched up".Also im getting my truck "rustproofed" which you can view what it is here if you dont know what it is Rust Protection | Ziebart my question is is does anyone have any experience with it?does it work?am i wasting my money?

 

[StreetKill831]

Their website gives almost no information on exactly what they do. From the pictures it almost looks like they spray some sort of foam inside the fenders? In my opinion that would do the exact opposite of protect. Moisture inside the fenders would be held there by the foam causing it to rust out from the inside.