I give up.  What's a "SI unit"?

So would I. There is nothing mysterious about the metric system.

   > A car built for a km/h market rarely has the speedo also
   > ticked off in mph increments.  A car built for a mph market
   > usually (but not always) has the speedo also ticked off in
   > km/h increments.

AFAIK, all vehicles currently manufactured for sale in Canada have
a large speedometer scale in km/h, and a smaller scale in MPH -- a
mirror image of what you see on vehicles built for sale in the US.

US federal motor vehicle rules require an MPH scale to be present
on the speedometer.  The small set of MPH figures on the speedometer
of a Canadian vehicle satisfy this requirement.

There will, as I understand it, need to be a label added near the
odometer, indicating that the reading on the odometer is in km.
(Note that I said "odometer" in this paragraph, not "speedometer".)

There might be other issues to worry about -- seat belts, bumpers,
and the like -- but if the car in question was built reasonably
recently (last several years), chances are it will meet US specs.

The biggest hangup for importing cars from Canada to the US (or from
the US to Canada) used to be conflicting seat belt rules.  However,
now that virtually all cars have air bags for both the driver and
the front-seat passenger, this is unlikely to be a problem any more.

In any case, though, my understanding is that the original poster
will need to get a letter from the vehicle manufacturer, certifying
that the vehicle (identified by make, model, year, and VIN number)
met all US "Federal Motor Vehicle Safety Standard" (FMVSS) require-
ments that were in effect when it was manufactured, with the possible
exception of minor labelling requirements.  AFAIK, the OP will also
need to submit a form stating that the vehicle meets US EPA rules --
which should be no problem as long as it was originally manufactured
with a catalytic converter, and the cat still works (or has been
replaced with a working cat), and the exhaust system is intact (need
to repair it if it's rusted out from road salt, etc.).

Even if the OP can meet all the requirements for importing his VW,
however, I'd strongly suggest he consider selling it in Canada
and buying a replacement vehicle in the US =unless= the car is in
=excellent= (and I =DO= mean "excellent") condition.  Consider the
following:

(1) If the car is still under warranty, will VW USA honour the
   vehicle's Canadian warranty?  Or will the owner need to pay
   for warranty repairs in the US up front, then submit the
   receipts to VW in Canada for (hopeful, eventual) reimbursement?

(2) Will the owner be able to obtain the proper maintenance or
   replacement parts at a VW dealer in the US?  His Canadian-model
   vehicle will NOT be identical to US models, and it's possible
   that US dealers may not have access to the exact parts (or even
   be capable of looking up the right parts in their electronic
   catalogue systems that are set up only for the specific models
   sold in the States).

(3) Any amount of body rust (a serious concern if the OP is from a
   part of Canada where they routinely salt the roads in winter)
   will =significantly= reduce the car's resale value in the eyes
   of an American would-be buyer.
   
(4) Even if the car is in perfect condition, many American would-be
   buyers are likely to be scared off by the "funny" speedometer/
   odometer in a Canadian car, preferring instead to buy a used
   car with a "regular" instrument panel.  Even though there are
   MPH markings on the speedometer, they're small, and many people
   will consider them too small to read clearly.  And as for the
   odometer, it's always going to be a "weird" reading that most
   American would-be buyers will be confused and suspicious about
   -- no alternate "miles" reading is available here.

(4) Moving a car could be costly -- certainly so if the OP is
   thinking of having it shipped commercially, or even if he's
   planning to drive it to his new home (consider depreciation
   for extra mileage).

So, unless the car is in outstandingly good mechanical shape, with
absolutely =NO= trace whatsoever of body rust damage -- or unless
the owner is hopelessly in love with his car, can't bear to part
with it no matter what the cost, and is determined to hang on to
it until it falls apart or gets totalled -- I'm not sure if it's
really worth going through the paperwork hassle to import it.

Rich Wales            richw@richw.org            http://www.richw.org