bio diesel is legal, even in the audi vw handbook it says its ok to use, ave used it for ages (50k miles no problem) , there was a place in york that used to produce it and had 3 pumps on the farm the guy has made a fortune and moved on now , the owner used to use it on his 55plate range rover sport, so its gonna be good enough for a poxy golf.
now there is no one nearby that sells bio diesel so its back to normal diesel, i find morrisons diesel good though, i seem to get more miles out of it then shell.
red diesel is also availble at the time it was about 55p u had to bring a barrel and fill it up and then stick it in your car, but its a hefty fine if u get caught, there was a story once about soem asian lads in ireland who managed to set up a factory which took the red out of the diesel but they got busted.
bio ftw.