As a former cab driver, I wish the Goldens all the best and good luck in their venture. I understand what you're doing, and the necessity for it, but I'm afraid you may be biting off more than you can chew. One thing I CAN tell you is this: Based on my own personal experiences as a late-night driver, invest in vinyl/rubber floormats and plastic seatcovers .. and maybe also some kind of nanny-cam/security camera system and/or ride-alongs with off-duty cops and/or hired security. Think of them like you would your spare tire and jack .. you may never need them, but if you do you'll be glad you had them! Good Luck!!