Has anyone on here ever installed or know about aftermarket HID / Xenon kits and how good they are. Basically I am considering getting some for my older Audi 100 using H4 bulbs and am in the process of doing my homework on them. I have searched the net and found a site I quite like which claims to sell kits that handle both dim and main beams in one unit (the bulb includes a solenoid that moves the position of the bulb relative to a shield to block the light from reflecting off the bottom part of the lens mirror when on dim). http://www.hids4u.co.uk/product_details.asp?id=44 Does anyone know this site, are they reputable, has anyone bought off here before and lastly has anyone installed H4 HID's before, ie are they worth it? (I know that VAG Parts advertise them but their H4's only have the dim beam) Thanks in advance for any advice or words of caution!