the people who have shouted at the top of their lungs about 'french fry cars' being free fuel have typically been the stupid, hippy types who dont know jack about ... well, about business. stupid socialist, "FU to Bush" types. nothing is free in this world.
this is an issue thats very well known throughout the WVO and biodiesel communities. the fuel tax is actually applied to regular gas and diesel as well. its a part of the road tax that is used for road construction, repair, etc. but to catch a biodieseler is literally unenforceable.
as far as the transportation of oil, they are applying an commercial waste fuel transportation law to waste oil transporters. this is pretty stupid, but its something the man can use to fine wvo transporters.
so what people do is they form a co-op to do a group purchase on the insurance policy, hand out magnetic signs w/ the co-op's name on it to apply on yoru vehicle when transporting used oil. they keep a log of the oil that was picked up and 'guesstimate' how much oil was consumed in their vehicles and pay the measly $0.18 per gallon.
the other thing people do too is NOT STICK F'G STUPID "I HATE BUSH AND THE OIL COMPANY' stickers all over their cars or the ubiquitous "RUNNING ON FREE FUEL - ASK ME HOW!" stickers. dont attract needless attention to your car. in fact, when i get my biodiesel car running, i am removing the "diesel" badge off my mercedes, provided it does not leave a noticeable good paint impression where the badge used to be.
dont worry folks, its still cheaper than $4.60 per gallon diesel and its easy enough to be legal and/or not to attract attention to yourself. to make biodiesel on the high end will be around $1.50/gallon
the other thing i wanted to add is that WVO guys are much more apt to get nailed b/c they usually run two tanks. open the trunk and the cops will know you are WVO'ing. so yet another reason to spend the time, money and energy and building your own biodiesel processor