You know, given what I know of how much a pain in the ass body work and paint prep is, I cannot for the life of me fathom a good reason to do this. What happens when it gets filthy and you attempt to wash it? Does some of it peel off? What about bug guts, tree sap, road grime, etc? Will this trap water between the plasti-dip and the body panels if there is a bubble?
Oooh, wait, I did think of a good reason to do this. If you're sick of people keying your car, this is like a slight layer of added protection. Possibly doesn't work as well for door dings, stupid kids and their bikes/scooters/baseballs/hollow heads, etc...
...and best of all:
Emphasis on Plasti-
DIP.
Sorry, I had to.