help with trailer wiring?

I had to do something similar with my Gen 1 because I couldn't find a plug-n-play kit for it (maybe one for another car like a Camry would work, as your link shows for a Gen 2, but I didn't know which.) An approach that lets you go back to stock if you want to later, without sliced and soldered wires, is:

After looking up the circuits in the wiring diagram, highlight them and click the orange Info icon (lower right corner) to go to the connector details. In the details for each connector, there's a "Wire Harness Repair" link you can click, which will show the type of terminals used in that connector, and the part numbers for repair terminals. You can buy a few of those at the dealer; they come with short wires pre-crimped into them.

Then you can extract the terminals you're interested in from a connector, and stick them right into this sort of Euro-style terminal block:



Just stick 'em all the way through, almost till they come out the other side. Don't tighten down the screw on that side (you'd crush the terminal); just tighten the one on the side the wire enters, which will land on the crimped part of the terminal. Tighten it down along with the wire to your universal wiring kit and the pigtail of a repair terminal, and click the repair terminal into the original connector. Wrap up the junction block in some insulating tape.

If you ever want to put the car back stock, just undo that and click the original terminals back into the connectors they came from.

The pic above shows a four-position Euro block; I usually just buy the longest ones, and slice off a chunk of as many positions as I need. The blocks are made for different wire sizes, too; the key to this 'reversible' hack is to get the size big enough that the terminals on the ends of the original wires can fit right in.

Did you buy the universal one before you saw that the Camry one would work?

-Chap