Riding the tank without getting off can easily be done at the end of a round. Simply have one person hold the last zombie, make sure you have 1,000 points, and get on the tank making sure not to get off until it arrives back at church. The tank will stop behind the station at generator 2, and will cool down for approximately 3 minutes. If you are doing this mid-round be sure you have plenty of ammunition before attempting this.
Note: An awesome tip for the Panzer boss units is that they cannot climb, shoot, nor kill you while on the tank. This is great for getting them down while remaining untouchable.
You could of course call the tank from behind the station at 2 and then ride it all the way back around until it returns to 2 if you desire as well.