>What about importing transmissions and/or bell-housings???  Is it the
>same tranny with a new bell-housing or a completely different transaxle?

I'm sure the parts are easy to import, once you find a source and
confirm they bolt up to older bus frames.  Complete vehicles?, that's
a different story (although they only have to be 15 years old to
import to Canada without hassles).

But be careful of 15 year old Mexican VW buses, a lot are used as
"colectivos" (community passenger buses) and have had the s*** driven
out of them....

>Coming up with our own inline4 and cooling system would be easy if
>there was a plug-and-play transmission solution available.

I4 engine? easy to find...radiator, plumbing etc?  a little more
challenging, but hey, Greg likes a challenge aka his Westfakia...
http://www.pottsfamily.ca/westfakia/

BTW, here's what late model Mexibus looks like for those who have not seen one;
http://www.pauldottrip.com/puerto_vallarta/pages/DSCN0771.htm