I just installed a set of HID bulbs with stock housings on my buddies '99. Here are my observations. Installation is pretty easy. Before you, start put penetrating oil on the adjustment screws so they are easy to turn, this will save you some cursing. After install, his headlights would not pop up but it seemed after about 5 mins that the car "learned" the HID's if you will and started to work as they are supposed to, kinda strange and also surprising. Before we started I had him pop up his stock lights and put strips of tape on the garage door to mark where the stock lights are aimed. After the install the lights were pointed at the tape like the stockers but there was "extra" unfocused light EVERYWHERE. It lit up the whole front of my garage (stock did not). He had lost one of the round black plastic pieces on the plastic trim part that wraps around the headlight and on the ride home he said unfocused light was coming through the hole and hitting the cars next to him at stop lights. Like I said, these are my observations and I am not trying to poke anyone in the eye
On a side note, 3 days after I installed those HID's I bought myself the euro t84 housings, high wattage harness and PIAA H4 high watt bulbs. They are awesome.