Re: first time going to the vet tomorrow. lost!
I think for this visit, you might be able to improvise a cage, if you have a small-medium size sterilite container. You can put a few fleece blankets in there for him to snuggle in. I'm not sure what you could do for the top, though...Maybe use the regular container top, but cut some holes in it for air. Then you can seatbelt the container in the seat.
I think, as long as you have the car at a good temperature, you'll be fine with the fleece blankets in the container.
~*~*~ Kelsey ~*~*~
RIP my sweet Lily ~ 6/12/08 - 1/20/12