A Porsche 911's back seats would be comfortable for perhaps a small child. But teenagers and adults would be very uncomfortable on long journeys.
The amount of leg room in the front seats of a Porsche 911 is 44.6 inches. The amount of legroom can vary each year.
The 2004 Porsche Cayenne has 35.9 in. of rear leg room.
The 2012 Porsche Panamera has 38.2 in. of rear head room.
The 2006 Porsche Cayenne has 36.0 in. of rear leg room.
The 2012 Porsche Panamera has 51.7 in. of rear shoulder room.
The 2013 Porsche Panamera has 38.2 in. of rear head room.
The 2014 Porsche Panamera has 38.2 in. of rear head room.
The 2006 Porsche Cayenne has 38.5 in. of rear head room.
The 2013 Porsche Panamera has 51.7 in. of rear shoulder room.
The 2003 Porsche Cayenne has 38.5 in. of rear head room.
The 2003 Porsche Cayenne has 35.9 in. of rear leg room.
The 2011 Porsche Panamera has 33.3 in. of rear leg room.