Ya know, there are some cars that just don't even have windows. Are they fair game for towing? Obviously one cannot show up in court and show the windows were available on the day in question because, well, they don't have windows.
but that's you. I know people with soft tops that never put the windows in. Whether they leave them parked overnight like that does not make them appear to be abandoned.When I had my Sidekick, I NEVER let the vehicle sit overnight with the rear window out.
If the car did not otherwise appear to be abandoned or non-functional, such as it sets there for extended periods of time, I do not see why the OP should not prevail regarding the costs.

