There is a market out there for drivers. A few girls have asked if my S/O could drive for them from time to time. If he could clone himself so he could be in more than one place at a time, he might do it. For the most part, it's not a drop off and drive away thing.
Plus, your vehicle gets tagged eventually. The police know what vehicle my S/O drives. They get curious when they see a guy sitting in a vehicle a block away, and tend to stop and ask questions. Even hotel staff figure it out when your dropping girls off all the time. Once the police figure you out, they make a habit of stopping and bugging you. They can't bust you for sitting on the side of a road, but they do like to harass you.
My S/O's typical answer to what he is doing is, "I'm monitoring night traffic."
He once had a cop say to him, "I think your up to something criminal." His reply, "Yes, I'm trying to get on the television show, Worlds Dumbest Criminals sitting here in a Tim Hortons parking lot drinking coffee and playing solitaire on my PDA. I'm waiting for the Brinks truck to arrive."
If you get into it, remember, the hours suck, and it's a hurry up and wait job. You need to get the girl there quickly and on time, and then you wait.