At the Cat dealer where I worked (now retired ),feild techs always took thier trucks home. We had radios in the trucks until 1995.We were then issued cell phones and the customers had the phone numbers.This was a big hit with the customers,they liked being able to talk to the tech that was going to come to them. I almost always went from home to my first job of the day. There was a lot of days I never went to the shop. The only real reason we had to go to the shop was for parts and do paper work. The field techs have work with each other so that nobody was over worked and everybody had work to do.I know this wouldn't work for every dealer,but it worked good for us.