There has been a lot of fuss about this in the vintage world where it is a very big issue.
Part of the problem is that nobody actually knows what the impact of increasing the ethanol content actually is and it varies according to the exact components in the car's fuel system but also how its used.
Allegedly the government are reviewing but .....
I believe there are already some "anti-ethanol" additives on the market to combat the effects, similar to the octane boosters/lead replacement.
In practice, I doubt if it would impact on a GTV in regular use and the odd tank full certainly won't do any harm but it could be very bad for a car left standing for a period of time.
916, Re your suggestion of using methanol: DON'T!
I use it in my race car and its horrid stuff. Strips paint, disolves or hardens many typs of rubbers and platics, strips plating off steel, dissolves alluminium and it burns in a very different way to petrol. You have to run a lot more ignition advance and bigger jets and its a bug$er to start when cold.
GTV and Racing Driver