HID lights

["john r. cummings" <jrc100@earthlink.net>]

My wife has an A6 with xenon lights. They're great on highway driving,
but on the back roads the low beams are bad. There is a razor sharp line
between brilliant light and total darkeness, because they don 't
diffuse. With every bump they dip down and on first hitting a hill they
point straight into it. The dealer has replaced an auto adjusting
sensor, and some wiring, but they still aren't as effective as the euro
lights on our 20V 200         (although they are brighter). Is this a
characteistic of these lights ? Audi claims it is. On the rural roads
around here there are way too many deer to feel comfortable . Could I
just replace the standard 55 watt fog lights with PIAA 1200 dichroic
lights which are of equal wattage and the same diameter?