HIDconversionsin an UP! would be an illegal modification. To legally have them you need, Projector headlight units, headlight washers & selflevellingmechanism.Unfortunately the Up! has non of these properties. You can fit them and they are a huge improvement over standard lights. Obviously you know that Up! headlights use H4 (472) bulbs which are one bulb with two filaments. So if you were to get a HIDconversionkit, you have two options: One is to get a standard H4 HID Xenon kit, this only has the onefilament so youdon'thave the option of full beams. Or two is to get a H4 HID BiXenon kit,whichdoes have the option of full beam but are a more expensive.
hope this helps,
As for your fog lights you can legally fit a HIDconversionkit too, Personally i like the look of yellow fog lights as i think they suit VWs down to a Tee. In our Tiguan i have fitted a H11, 3000 kelvin HID kitwhichare very bright and are yellow, any HID kits above 5000kelvin in colour temperature are white/blue.
Yellow is the mostefficient for use in fog, if you look at Le mans or rally cars you will notice they have yellow fog lights, this is because yellowdoesn'treflect of fog light normal headlights.
I would stronglyrecommenda HID kit for your fog lights as they do make a world of difference they do take abit of work to fit, but they are worth it.