As mentioned above, V8s are the ONLY way to get HID for 2005, but base V8's still dont have them.
Xenon and High Intensity Discharge, as well as Gas Discharge and Twin Gas Discharge are all the same thing. It just means that an inert gas is burning rather than the traditional filament in a halogen bulb.
Retrofits are possible, but I strongly recommend against it. There are companies out there that make plug and play "kits" that allow you to adapt your stock wiring to power a Xenon ballast and bulb, which would fit into the space normally taken by the halogen bulb.
There are several reasons this isnt recommended. One, your stock wiring is designed for a constant 55w pull from the halogen lights you already have installed. Xenon systems actually only pull 35w at normal operating levels, which is fine. However, at startup Xenon lights place a massive load on the wiring to get the bulb ignited and burning, this can cause problems down the road. Secondly, and arguably most important, the projector glass that is in a car designed for Halogen, is DIFFERENT than that of a car designed for Xenon. If you merely throw a kit in there, you will scatter light all over the place and BLIND oncoming traffic.
For this reason, the BETTER solution is just to go on ebay and FIND the stock HID factory headlamp assemblies and REPLACE your OEM halogen ones. This is a little bit more expensive, but not ALOT, and you get a factory look that you cant spot a mile away as being fake.
