After drooling over the inline heater boosters available and trying to
justify the $69 plus shipping, for what looked like a fan and some tape, I
finally found a solution at a marine supply store.  Attwood's 4-inch,
water-resistant turbo in-line blower, used for ventilating bilges on boats.
$25 here in Richmond, they had two in stock, that look exactly like the fans
pictured in those kits.  They also had the 3 inch fans that look like the
ones pictured in the bug kit.  I installed mine next to the gearshift box,
right above the spare, fits nicely, really helps the alt/blower.  I have not
done the insulation(it really doesn't get that cold in Richmond) but did
replace the center section of holy tubing with some 4" ID alum dryer vent
hose (it is too big inside to fit right over the vw collector, but fits
tightly over the oem tubing, which fits tightly over the vw collector. I also
bypassed the heater boxes as they were rotten and pricey, I will fix them
back to original when time and money become cheaper.  Temporary Temp control
will be by blending fresh air into the airbox, just like them water boxers do!
ANYWAY, it gets pretty dang hot and that's what I wanted.  If you want more
details on how to spend a fun day at the junkyard and parts stores and under
your van, fee free to p-mail me.

Toasty warm in Richmond, P