wow, thats sad. but he should have known better. on the last pull the motor was shaking because it was breaking up. it was breaking up because it was too rich to light off. lots of extra fuel+tight engine compartment= disaster.
as for why to do it. easy, its different and just downright stupid fast. each one of those motors in that car was good for 300+whp. and you would be surprised at just how easy it is to put 2 drivelines in a VW. the only reason more people dont do it is 2 drivelines cost a lot of money. I've seen a few twin engine cars myself and they are always a treat. i got to watch one last year at a car show put one tranny in 1st, the second tranny in reverse, and the guy just sat there doing doughnuts on the center axis of the car, unreal to watch.