I've had HID's for the last 3 years. They really don't help night time vision at all when installed in the 97-03 housings. I only put them in for appearance. After a 4 hour drive in the dark this last weekend, I decided that I will be upgrading to retrofits, as many before me have recommended.
If your heart is still set on plain old HID's, I'd suggest getting 9007 harness addapters from ebay. If you have to splice in a resistor like I did, this makes for a nice plug-n-play option for easy reversal.
2x 9007 HID Conversion Kit Error Free Load Resistors Wiring Harness Adapter ,4C | eBay
or
2 PCS Wiring Harness Connector 9004 9007 HB1 FB5 LED Light Bulb Extension Socket | eBay
good luck
