http://www.golfgtiforum.co.uk/index.php?topic=149135.0
I've bought one of these relay upgrades for the headlights, seems like the guy who made them originally found 6 in a box or something - however I think they're all gone.
If anyone with a MK1 or MK2 really wants to do this upgrade (and I can tell you how good it is once mine's fitted) then I'm happy to make some more; I have been known to wield a soldering iron in anger before (ex engineer).
As I understand it, instead of routing the power for the lights halfway round the car and back (which gives you voltage drop and limits the ampage you can draw) a relay dumps raw battery-terminal power into the headlights, activated by the original headlight feed (AFAIK).
Lemme know
(Edit - there's 3 left as of 11:45 - link above, £25)