Hmm, a bit unrealistic of the OP.
When we bought the bus in my sig, we did not drive it personally until after we paid for it. Our test drive consisted of the salesman doing the driving as we went anywhere directed.
However, we bought from someone with an established business and a very good reputation. It was explained before the deal that due to insurance, we would not be able to personally test drive the bus.
Now, three years and around 50,000 miles later, we are still very happy with the purchase and would do it again.