AutoGas question.. Jay Honeck, Jim Weir.. others..

The folks here who are running autogas.. I have a question for you.

Preface: When I was tasked by my volunteer fire department 10 years ago
to stamp out fuel credit card abuse and fraud, I secured the services of
a certain brand's fleet card system. The sales vendor who set up our
account told me that any of our OFF ROAD engines were eligible to be
billed free of the state and federal highway fuel taxes. In the fire
dept's case this was for generators and free standing pumps.. but our
"off road" gasoline useage was so light that it wasnt even worth the hassle.

So.. Since aircraft (with the exception of Mr Moller's wannabe Skycar
and a few others) are not considered licensed motor vehicles for the
purpose of the fuel taxes, do you guys make an effort to obtain fuel
with a special account that gives credit for these taxes? In Texas the
amount is 38.5 cents/gal and over a year or so that can add up to real
money (especially in light of the discounted price of autogas compared
to 100LL)

I'm presuming some method of accounting would be needed in the event of
an audit.. but just wanted to see if 1) anyone else was aware of this 2)
does it still exist and 3) does anyone do it?

I figured Jay Honeck would be a perfect example of someone who could do
this, since he has his Mighty Grape (TM) fuel shuttlemobile. If the
Texas rates apply I would guess this could drop Atlas's operating costs
by $4-$6 per hour (40 cents x 10-15 GPH). Fillup of the Grape's 60 gal
tank would be about $23-$24 cheaper. Every little bit helps.

I was planning on contacting Fuelman/Rushce about their fuelcard setup
but havent gotten to it just yet (many months out from flying the
Velocity with auto conversion)...

So.. anyone have input, feedback, comment?
Dave