Haven't actually tried it yet, and I'm sure as hell not going to in my car!

BUT, this is a really interesting concept, and the best way to check it out is through a test... I'm thinking once the weather gets warmer again, I'm going to find a cheap (free is good) lawnmower engine and do a series of tests. First up, which can be done any time and is a really good call, is to soak some tubing and o-rings in 100% acetone for a couple days (weeks?) and see what happens. This is awfully conservative, but obviously if everything holds up, then obviously diluted quantities won't hurt fuel lines. Then I'll have to figure out how to quantify the results of straight gas versus gas with acetone in the engine runs.

I'm an engineer (not mechanical or chemical), so this is really interesting to me!