Found this while looking though gates website for ethanol resistant filler neck hoses.

http://gatesaustralia.com.au/spacertool 

when I worked for CBC some years ago, who are a major distributor for Gates, they were definitely seeing this type of failure back then. (2000-2007). With VW applications we are lucky as we have good access to the timing belt and can easily get the clearance without guesswork which is what happens in the original Subi application as there is not much room between the timing belt and the radiator.

do CBC sell hoses?