How do you insure two cars same address with only one driver?

The same way you insure one car. It is not that unusual for a person to own two vehicles. This is where it pays to have a local agent that you can go in and speak with. An on line company where you never speak with the same person twice is not the way to go with insurance. The car that you normally drive to work or school will be rated as such and the second vehicle will be rated as an extra vehicle with pleasure use. Be truthful and if someone else drives the car even occasionally tell your agent.