Although this may only pertain to Vanagons with conversion engines, it's worth reading what one of the more prestigious Porsche shops thinks about a (what RedLine calls "insignificant") 10mm hypoid offset, as found in BOTH Porsche & VW transaxles:

"In order to fit a compact transmission with the requisite features in the 911, Porsche uses very steep hypoid angles on the ring & pinion gears. This make these parts, the most highly stressed part of Porsche transmissions. This requires a GL-5 rated lubricant to protect these components against premature failure. Ring and pinions are problematic areas of these transmissions and require careful setup for any 901, 915, 930, or G50 used for competition or high-horsepower applications."

(Steve Weiner and Jeff Gamroth are well-known in Porsche racing circles.)
http://rennsportsystems.com/letstalk-2/4-how-to-make-your-porsche-faster-transmissions-clutchessscluct/
http://rennsportsystems.com