Please correct me if I'm wrong but non OEM HIDs are not road legal on the dip beam or driving lights. This is down to the lense and the shape of the reflector which was designed for H4, H1 or H7 throwing the light beam all over the place instead of focusing it properly. The other reason is that non OEM HIDs take a couple of seconds from cold to reach operating output which means if you suddenly need dip beam, it isn't there. Also, switching from Main to dip will leave you with a temporary black spot. Some of the aftermarket HIDs have an electro mechanical device that physically moves the bulb, probably not a good idea. There are also dual bulbs that have a hologen for the dip and HID for the main beam but I've only read bad things about these and the only place I saw them for sale was Fleabay.
On a more positive note, If you would like to improve the headlights for out of town driving, have you tried the Osram Nightbreakers? Ring do a +100 bulb too and that works well. I've been using the Nightbreakers for about five years and there really is enough of a difference to justify the price. I had an HID kit on my Accord but it was only on the high beam, and after the first couple of seconds on main beam, the night just disappeared. On the Accord, the dips stay on when you go on main beam but switching back to the Nightbreakers only on dip was ok after the HID mains.
Oh, and one last thought on HID dips, you will piss everyone off coming the other way, no matter how low you aim them, even a lot of factory equipped cars - Mercs, BMWs, Audis etc, are too bright.