This is my first foreign car and now I get it. This car is quite impressive all around. I love this car. It is comfortable, enjoyable, affordable, even if the gas mileage isn't stellar. It sure beats my old 2006 PT Cruiser which was getting 17 mpg city. You can't help but smile when driving the Beetle. It sticks to the road and is very quick and I feel extremely safe in it even though it is a small car. Don't over think and criticize the back seat. It is more than enough. So the head room isn't excessive, I have had 4 door sedans that were just as bad. Enjoy the ride.
Everything. The seats' adjustability, the interior room, the strong driving position, ease of driving, gas mileage, quick throttle response, 5 cylinder torque and horsepower on demand at lower RPMs, fold down seats with removable seat head rests, fits in the garage. I can go on and on.
I would suggest making the back seat adjustable so that it tilts back about ten degrees and make the back head rests disappear into the seat when not in use. They do block the rear window a bit.