Are you looking to add a window release switch? To do that you would want to access the GRN/BLK wire at the trunk, i'm not sure where the "smart entrance control unit" is located. The wires are behind the plastic cover over the inside of the tailgate. It should just pry off, don't forget the bolts behind the handle on the inside. All you would need to do is run a single wire from that GRN/BLK wire to the dash, or where ever you want to put the switch. Than the ither side of the momentary switch to Ground, any metal frame surface should work.