As I have posted a few questions for Vanagon owners, here's my latest: 
How well rustproofed/undercoated are Vanagons in the 87-91 vintage. I 
have heard there was something done to them at the factory, but have 
no confirmation nor user data. We are in the Texas Gulf Coast where 
corrosion abounds and this is important to us. Many of the older 
air-cooleds don't hold up too well down here due to rust/corrosion, but 
I heard the later VW's of all type have factory 
undercoating/rust-proofing and should fare better. Any feedback 
appreciated.
Regards
Mark B. Magee