My kid is thinking of getting a p/u and trailer and doing small hot shot loads up/down I-5, anybody have some info on that sort of thing?

I have a friend who does hot shot. He primarily runs California, Nevada, Utah and Idaho. He seems to do well hauling cars.

Be aware that "My Kid" you're refering to has to be 21 to run a commercial rig interstate and will need at minimum a class B license also.