I found some surface rust on the lip of the doors on the MPV and went to see if Mazda would cover it, since this is appearantly a common problem. No penetration = no coverage.
Anywhoo the point is Carstar (who initially suggested I try Mazda) suggested it would be ~$400 A DOOR to grind and repaint a 1" strip of metal ~2' long. The Mazda dealer was kind enough to get a quote from their body shop and quoted over $500 A DOOR.
Putting this into perspective, as I mentioned earlier - the Sentra had two (high visibility) full panels repainted by the dealer - including dismantling the doorhandles, bumpers, trim etc etc etc caus no-one tapes, for ~$1,000.
So: Two big brand name shops want a thousand bucks on the Mazda to grind and respray a comparatively small area and something not immediately visible; compared to a thousand bucks for two full body panels.
I got a quote from a local, recommended body shop in the west end - both doors $400 TOTAL on the Mazda.
Moral to the story - big name bodyshops will plunder the uninformed.
Just comes down to who you got the recommendation from for the other bodyshop....but it sounds like you are going insurance for the loaner.