Best Van/Minivan//Station wagon to sleep out of as a courier

[akrvbob]

In your situation, the Prius seems the very best choice. They have a very surprising amount of room, 40-50 real-world MPG, and you can run air conditioning anytime you want and not see hardly any less MPG, even running it overnight. Hook up an inverter to the drive bank and you've got all the power you need.

 

[John61CT]

I suspect a Prius in decent-looking condition (for a "courier"?) available for under $3500 would be needing a replacement battery pack sooner rather than later.