because of the different lengths of the HID bulbs over standard halogens, once you change halogens for HIDs the beam alignment will be too high.
I've got an HID kit in my Octavia, and needed to have the beams aligned as soon as the kit was installed, as they shine too high.
That's your
problem.
And as Lee says, 8k are far too blue, and will attract too much attention from the police. End of the day, HID kits are not road legal, and lights that are obviously too blue is just advertising you have an HID kit fitted. You're basically saying to the police -- "Look at my nice blue illegal lights and pull me" I'm not having an argument about the legality -- as I've said I'm running HIDs myself, all be it in a car with projector lights.
The best light output from HID bulbs will be got from 4300k -- these give a much whiter light.
Mike