If you are running company business, you should be on the clock, period. If you are a W-2 employee, they cannot get around liability by keeping you off the clock.  You can be held accountable for any accidents as well as them and you want to make sure they either give you a company vehicle or cover you with indemnification if you get into an accident or provide additional insurance.  Check with your state's labor department on any regulations or orders it may have on this matter.