Are there any decent and reasonable portable car vacs out there?

Read good things about the Dyson (http://www.canadiandriver.com/articles/pw/dyson.htm) and can relate to the point made re "You remember those plastic 12-volt vacuum cleaners you'd plug into your car, hoping to clean the carpets without having to drag the canister vacuum from the house to the driveway? They were such a disappointment. I recall actually picking up pieces of dust and lint from the mats, and putting them into the "vacuum cleaner," such was its uselessness. Those devices made a lot of noise, and that was about it. "

But at $170 bucks, I'd rather drag the 35 foot hose from my central vac (when I'm home)

Looking at some more reasonable options.

I'd even settle for a 115V unit ( as I have a spare inverter)...and the wifes new Santa Fe beside the G35 has one built in - pretty cool - a 115V 3 prong right there in the trunk.

Some users seem to like the Simonix units at $99 here

Thoughts?