You can see it in the photo I took once I had safely stopped and before I proceeded to escort him/her to the ground outside my car.
But let me tell you, that was some nervous driving for a couple of minutes there.
And no, I didn't just squish him. Partly because I don't do that with spiders, and partly because ewwww, then I'd have to clean that up.
But gah! SPIDER IN CAR! IN CAR!!!!