After looking for information without success, I ended looking by myself, so after spending a lot of time checking all the wires, this is a few pictures of the (working) result.
You need to remove the luggage rear plate, the luggage side finisher and the lower luggage floor spacer (INT-34 from http://www.nicoclub.com/FSM/EX/2008/
I installed this power module : http://www.uhaul.com/MovingSupplies/Wir ... wer-Module
and this trailer hitch : http://www.autoanything.com/towing/73A3 ... 11353.aspx
Yellow on green : left turn signal
Green on blue : right turn signal
The black wire coming out of the bumper is connected to the battery.
This is how to fix the ground :
Installation overview :
Brown on red : Tail light
Red on green : Brake light
(Fixed on the left rear lamp connection)
I hope it will help a few of you.