Parts from Audi not sure on VW
2x 000 979 134 A- wire
2x 000 979 133 A- wire
1x 1J0 973 722 A- connector
1x 1J0 973 822 A- connector
Take the pink and orange inners out of the connectors, plug in the wires and solder in the middle. You should end up with a 4ft length which I wrapped in heat shrink tubing.
That mpg is with a mixture of A and B road driving but start hoofing it round and it'll guzzle. Obviously the trip computer will be out with the injectors but we'll see.