Grab a shoe box, put some padding inside, make some small air slits... place in a closet for about 20 minutes before your gonna leave. The darkness will make the cham think its night time. They will just fall asleep. Then put the box in a low lit area of the car keep the temps kinda cool as if it were night time. I have done this for vet trips. Jake just slept the entire way. When we got to the vet we opened the box and he woke up, a bit groggy but after a few minutes he seemed just fine.