Just an update on the issue of the undercoating on our new carpet van melting and dripping on customer driveways, and what i've learned.
GM has refused to do anything about it. They said there is no special warranty that they have agreed to with Hydramaster. It is the job of Hydramaster to access technical information of GM, and build/install their units accordingly. They said it's the heat of the truck mount exhaust that is melting the undercoating and apparently Hydramaster/Bay Area Floor Machine should have installed a heat shield.
Hydramaster has blamed the undercoating and refused to do anything.
Bay Area Floor Machine, after months of stalling and doing as little as possible, has also failed to do anything about it (and will, no doubt, continue to sell GM vans to unsuspecting truck mount customers).
We spent hours scraping off as much undercoating as we can access and will be fine until summer comes around. I don't think the missing undercoating will affect the van since we have mild weather (no snow and salt that will rust it out for example. But we will need to be choosy which jobs we send this van to this summer until the residual undercoating appears to have stopped dripping. It's a large area and we tried packing cardboard around to put under the van but that looked really cheesy and wound up getting on other things in the van between jobs.