can I install a xenon kit on my '04 prius?

You might get a better response if you move your question to the Prius Modifications area.

 

its easy.
step 1: sell your unloaded prius to someone older who doesn't care about things like navigation system or h.i.d.'s
step 2: buy a used fully loaded prius on cars.com from a private seller.
look for foglamps because the h.i.d.'s are packaged with foglamps, so if a prius has foglamps you don't need to ask the seller if it has h.i.d.'s because it does. The seller may not know what those are and you don't want to alert them that the car is more valuable than they thought or you won't be able to negotiate a better price.

 

AND . . . it's not just a matter of ploping a HID lamp into the car. The reflectors on a HID model Prius is different than that on a non-HID model. HID Prii also have a sensor and light leveling system to prevent the HID lights from blinding oncoming traffic if you weight down the back of the car with cargo.

You may end up with a bastardized system which shines the light God know which directions.

 

He doesn't care about any of that stuff. He just wants to "rice out" his Prius.