Dehodg,

What you want to do with that T-Connecter is get is wired up to the left (driver's) side then run the harness through the two pieces of sub-frame over to the right side. The control box (big square plastic box with double-sided tape)...dont' try to stick it to anything (will probably fall off then you have to open up the driver's side panel to get rid of the rattle). Just bring it up and let it lay in the triangular storage compartment on the driver's side...the tail piece with the trailer plug can just be coiled up there also until you need to use it. When you want to plug into a trailer just bring the tail connecter out through the hatch, plug it in and close the hatch. When you are finished with it, just stow it back in that triangular compartment in the floor on the driver's side....EZ

PS: Make sure you test and see that all the lights are working properly before you button it up. If you don't have a trailer to test the harness, go to an auto parts store and for about $2.50 you can get a test plug that has 4 green lights on it. Plug it into your harness; each one of the lights means a different thing ie: one light being lit means tails are working, two other lights will blink for right and left turns and then those two together will light up for brakes.....simple check!!