At long last I have installed the HID kit in my G-Max...
I had wanted to by a kit for quite a while - at the Motorcycle Expo there was a guy selling the kits - he quoted me $200 for a single globe kit, I'm not sure if it had high and low beam or was a single beam - can't remember. Gave me some big spiel about how they were the same kits that BMW put in their cars, they are the best kits available, he is the sole importer of these kits...blah blah blah...
So me gets on eBay - $72 later and I have a nice HID kit sitting here - bi-xenon (pretty name for high/low beam)
So it sits around here for a couple months - me gets adventurous just over a week ago.
What started out as something relatively simple turned into a bit more than that - the bloody ceramic end-piece on the globe wouldn't fit through the hole in the back of the reflector assembly, so muggins here thinks "ah well, I'll make the hole bigger!" - oh - I can't get my Dremel in the confined space - ok, I'll take the nose cone off!
Now, for the life of me I couldn't work out where exactly the plastic tabs were that hold the thing together after you undo the screws. No probs, I'll remove some other plastics!
Don't you love how things snowball?
Well, I couldn't work out how to get the back panel of the front bit to move, so I started taking bits off until it moved! So sue me!
Anyways, this gave me GREAT access to the rest of the scoot for running wires back to the battery and stuff...
The kits comes with globe assembly, ballast, some switch box thingie, cabling...
Essentially the HID ballast draws its power directly from the battery - but you have to wire the control box to the existing H4 connector so it can switch from low to high beam and back. As seen in the picture below, I attached spade connectors to the wires and stuffed them into their respective spots.

The ballast and control box are stuffed in the front space as well (a tad hard to see; I should have taken a photo before putting the plastics back on):
The control box is directly behind the horn; the ballast is the silver thing with the black and yellow sticker.
I ran 10 amp wire back to the battery, with an inline fuse; nice red/black colour coded wiring running through with other wiring that goes from front to back. Nice and professional-like...10 amps is heaps; startup wattage is 70W max, running is 35W; this is 6A and 3A (approx) respectively @ 12V.
Now back to the reflector - sadly I didn't take any photos of this as you can't see how much of a TOSSER I am!
I attacked the hole at the back, where the globe enters the reflector, with a sanding wheel on a dremel. Now think of what happens when you grind away plastic at high speed? Can you say cornflour? 'cos that's what the consitency of the dust was! The complete inside of the reflector assembly became coasted in the finest dust you have ever seen! "No probs, I'll blow it out!" Can you say IDIOT?
Needless to say blowing didn't work - neither did copious amount of water. Neither did yelling, or crying, or dancing around on one foot after kicking the house...
"I'll separate the reflector from the clear lens" - can you say GLUE? They sure as heck don't mean for ANYONE to EVER separate those suckers once they are put together!
It's too late now - I'm committed. 3 hours, 3 Dremel cutting disks, two knives, a screwdriver, some bandaids later...It's apart! WOOHOO!
Upstairs to give it a careful wash in the sink - knowing it's just silver float on plastic, expecting the whole lot to flake off - thankfully it didn't...
Over to Dad's place - back half an hour later with a caulking gun and some silicon tile sealant - goop it back together - oh great why did I grab WHITE sealant? Ah well too late now...It don't look THAT bad...
Back on with all the plastics - wow I astonished myself, a screw in every spot where there should be one, none left over...That's gotta be a new record!
Start 'er up - W...O...W...!!!
Check it out for yourself:

Pretty huh?
One last photo, showing the globe and the hole I cut out of the reflector:
Oh - how does it achieve high/low beam? Well, normally you have two filaments in your globe - one closer to the back of the reflector than the other. According to some law of optics written by some dude I don't know, when you change the position of the emitter, the angle of the scattereed light changes - thereby giving you one beam pointing to the ground close to your scooter - then when you switch to high beam, it's pointing further away.
The bi-xenon HID globe achieves this by having the glass globe bit slide in and out, moved by a solenoid or something. Nifty hey?
I do have one problem at the moment: my battery is pretty well stuffed so when it's low on charge, I can't run the headlight, even when riding along, until it gets some charge back into it. The G-Max seems to not put out a whole lotta excess current from its charging system...And because of the nature of the Xenon High-Intensity-Discharge system, it's either on or off - it won't glow feebly like a filament globe does when you are sitting barely idling at the traffic lights...All will be ok once I have a new battery im; it runs perfectly with the battery fully-charged...
Link to a coupla more photos:
http://picasaweb.google.com.au/sgian.dubh/GMaxHIDKit?authkey=5c_3m5QH8Z8
All in all, I would recommend HID to anyone - however I was lucky in that my scoot uses an H4 globe, whereas I have noticed a lot of scooter use weirdo globes - so you may have to make up a bit of an adapter to locate the globe properly into the back of the reflector.