Backseat Confidential (2001)

Poor Stephanie, a lonely taxi cab driver in the big city. to endure long days, Stephanie often fantasizes what it would be like to be in the shoes and pants of several of her customers. Every now and then Stephanie's break in monotony comes when she picks up a horny couple that just can't wait to get back to their place to get it on. But for this horny taxi cab driver, watching just isn't enough...why watch when you can join in?