Body Decomposition

I have a 2001 Silhouette GLS - and live in a rather difficult climate to keep it presitine, with the amount of road salt used during the winters.  This year seemed preticularly bad for rust appearing on my van.  These are the problems I've experienced....

Hood - Bubbling.  This is not 'rusting' but it is oxidizing, and it is appearing all over the edges, seems anywhere there is a seam.

Front Fenders - Rusting.  Right infront of the wheel, where the fender meets the bumper - on both the passanger side.  I went though a car was this spring, and the high pressure blasted each side, revealing rust inderneath about the side of a quarter.

Rear Fenders - Rusting.  It seems the rust perforates from inside the wheel well out - where snow and salt sit (in my climate).  I have had both sides repaired before, but it just came back much quicker this time.  This seems to be quite a common problem on the Chevrolet Venture aswell - not so much the Montana as it is covered in plastic.

Trunk Lid - Rusting.  Around the seam, at the bottom of the trunk where the inner and outer piece was welded.  Another spot that salt seems to stick to due to the vortex caused by the vehicle.

Trunk Hinge - Rusting.  When you open the trunk, look carefully at your hindges.  My passanger side hinge has not rusted, but almost rotted completely out.  The GM dealership I deal with say that this is quite a common problem, as water has a tendancy to pool there.

If you live in Canada, GM Canada offers a 6 year OR 160,000 km warrenty on any PERFORATING rust, this means it has to make a hole in the vehicle.  If you see any of your paint bubbling, then it has perforated through.  Don't let your dealership say otherwise, as it is considered warranty work and they don't want to do it.

Has anybody else in a snowy climate experienced these issues?