I sleep in my OB often on paddling trips. I use this set up...
twin size coleman air mattress and sleeping bag. and this DAC tent.
works awesome for more room, bug net and ventilation (I'm 6'4").
sets up in minutes.
on nights in low 20s i'm plenty warm with 0 degree bag (though i do get some frost/condensation on inside of windows).
it's been dry on some pretty heavy rains.
DAC Inc., Explorer 2 Tents for SUV, Minivan, Sport Utility Vehicle camping!
I just uploaded an image to the gallery. testing on a cold stormy night in driveway...