Yes, it is in the passenger fusebox. It is listed in the handbook (for a 2004 facelift) as 22 trailer but no value. It is physically located on the 4th row up from the bottom and the last on the right.
The fitting instructions for the kit give the info to use this position.
"Don't think of them as problems, think of them as opportunities."
"OK, I think I've hit an insurmountable opportunity!"