We had a cat once that was a real pain when travelling, she'd be all around the inside of the car, round the back of your neck or front of your face, up under the dash, anywhere she could go. She wasn't in a panic or anything, she just kept moving about.
We didn't have a crate for her, and didn't have much room in the car for one anyway, so I put her in an old flour sack and tied it around her neck (She didn't know what was coming the first time so she didn't struggle). First time was OK, she just flopped down on the seat and meowed pitifully all the way. But trying to get her in the sack again for the journey home was quite another story. For a real fun time just try to put a cat in bag when it doesn't want to go in. Took her four or five times before we could get her bagged peacefully.