No a clock is irratating if they are use to it. You will have heat in your car. I would not worry about that.
I take a k-mart towel bath size that is fluffy. Cut in half, then the second half cut again. Put the larger pieces in the bottom, with a second half on it. If the pup gets sick it soaks it up, and taking off the top towel solves the problem of it being wet. I have like 3 sets of these. Old kitchen towels work too.
I am sure he will be fine after the first few minutes cry- or stop and go to sleep.lol... Galina never said a word, Zubin HOWLED for 10 minutes then slept.. lol.. Femka was silent but she is an adult.