Kinda reminds one of the Messerschmitt 'Kabinenroller', see: http://www.pcsystems.com/messerschmitt/mess.html
it was availabel as single and two seater (same config as the VW, one behind the other), and in 3 or 4-wheel config. The 4 wheeler was the Tiger 500.
Didn't quite get the mileage of the new VW.