Here's some thing's I've put into the Pri..

Mods:

Lights
Custom always on additional power outlet for interior lights: 7 color remote controlled LED cupholder, vents, glove boxes, under seats, seatbelt connectors, RED LED replacement of factory bulbs in domes, doors, license plate; Blue/Purple/Red LED's in front grill.

Video
Ipod video integration, Playstation2 with wireless remotes, 2 input video switch, 2 switched additional LCD screens in console for rear viewing, video amp

Audio
2 10" JL W0's in Custom fiberglass boxes, Viper450x5 amp, 6" Kickers in rear doors, 6.5 inch fusion components in the front.

MISC
All weather floor mats, 3 inch antenna, LeBra, mud flaps, Electric Vehicle Mode

LED Lights
On the bottom of the pic, the left side of the console is the controller for the LED's in the vents. I chose to put these on different controllers than the floors so that I can have the seats and body of the car glow different than the ground. Both locations have 7 color variation.

LED Remote underseat Lights
here you can see the red lighted switch (top left) which I tapped off the input to the fuse box

And here's the octo coupling where all the lights are run from (under the cupholder)

Here are some more images of the cupholders and the vents