It isnt just VW.  Ford and Chevy vehicles made to the same identical specs
in Canada for sale in the US and Canada have the same problems.

The speedo part is probably a cert for the "true" mileage to be recorded,
but when the vehicle is over a certain age many states just automatically
stamp it unknown or out of range.  This is at the state level and when I did
some cross border drives with vehicles several year back they never looked
at that on the border.

The conformity paperwork is the nightmare part if they need it.

At a place I worked at we did a vanagon conversion for a Canadian customer.
The trick was that we had to use a certain year vanagon and not the newer
one that was in better shape.  The newer one needed different and more
restrictive paperwork to cross the border.

And now for one I just recently ran into with a guy that bought a camper
trailer in Canada.  He couldn�t find out what paperwork was needed anywhere.
He went to the local dmv here in Colorado purchased a temp plate drove back
up to Canada and hooked up the trailer and drove to the border.  They
checked the bill of sale paperwork on the Canadian side and waved him
through.  On the American side they had him scale it (had a bunch of stuff
in it) checked the weight slip and waved him through.

I am told going the other way with a trailer camper is another ball game
with some interesting tax papers.

jimt