Start off with Larry Chijner's Caddy. This thing is a work of art!!!
The trunk it fully motorized and all kinds of panels flip and slide out. The pistol grip in the center console is the remote control. He also rigged up some track and volume controls to go on the arm rest of the passenger side door!
He also has speakers on the outside of the car in various spots because he has a pre-recorded demonstration so when he does Intall, he turns it on and a narrator starts talking about all the stuff while he walks around and points to it.
He also had a 12" sub mounted flush in the floor board!