Actually it depends... VW's W12 engine its a serious monster, i wouldnt call VW weak. You will find this monster of an engine on: R8, Spyker C12 LaTurbie, Spyker C12 Zagato,
damn that chopped blue one has a porsche 914 v6 boxer engine in there....
You will be surprise, you can easily stroke a 1600cc Beetle engine to 2140cc for less than $1500, add to that a decent t4 turbo set up and the fact the car is super light, and you will have a car that does the 1/4 in 12's for less than $5000.