I've always been intrigued by acid dipping a uni body. Ideally, it would attack all the spots on the body that are hard to get to by any other method. But, if the car was anything but but solid with only surface rust, wouldn't an acid dip cause some of the more heavily rusted areas on a typical older car to basically disappear? Basically, is acid dipping only a process that safely works for cars that are already in pretty good condition (metal wise)?
If you go to site I posted in the second post, they have a Q & Q page that will answer every question you ever had.
MOST places (and there aren't many to begin with) don't do an e-coat. The big difference being the business model - dippers are in business to remove coatings, e-coaters are in business to apply them. I only found one (in Vancouver, Canada) that offers a zinc coating after stripping.
