Cars needing fuel has always been a major problem at most dealerships and I would be very surprised when you did go for a test drive if there was more than a quarter of gas in the tank ?,,, so you ask yourself why don''t the used and new car manager just top up all the cars. Without going into detail 99% of staff from every department would abuse this type system.
A real pro salesperson during a test drive will point out a few features that may be of interest and will answer all questions but beyond that will only concentrate on body language looking for the hot button.