Tekonsha 119191 ModuLite HD Plus Protector w/Integrated Circuit & Overload Protection Trailer Light Power Module & Installation Kit, Can be used on a 2 wire or 3 wire system

Picked this up for my 2018 Tesla Model 3. Install went very well. Directions are quite good, and a quick search will lead you to the proper wiring for the car. The only thing I did differently and would recommend would be to use better T connectors than the cheap blue ones in the package. Here's what I got and would HIGHLY recommend. https://www.amazon.com/dp/B072N7S3DLOther than that, 100% perfect. Wires were long enough to reach both sides and 12v under the rear seat. Ample crimp connectors to get everything together, etc.

Follow the directions and it’s an easy install. No need to splice and dice the electrical harness

This kit is awesome. Universal, so I can buy again and fit to any vehicle in the future. Instructions were actually helpful, it provided a key for what each wire does, as well as explains different kinds of turn signal/brake light systems to give you a better understanding of how your car operates. Includes all the hardware you'll need, although I went out and bought a pack of 4 "T-Tap" connectors from advanced auto, just my preference. According to a trailer light tester it all works wonderfully first try, excited to pull with this setup. Only other thing I used from my personal electrical box was a multimeter to determine which wire did what on my car, and a smaller terminal crimped on to the end of the unused red wire (in my case) so I could ground it. But they also provide a U-shaped connector and sheet metal screw if you don't already have a nearby grounding point in your car.For other model 3 owners: I went for the 12v power under the rear seats on the passenger side. Under some foam there's a red rubber cap and a nut securing a thick 12v wire running straight to the battery, saves the trouble of running a wire all the way to the battery directly. Added the fused wire directly to the underseat terminal, then crimped that onto the long black wire and ran that through the trunk behind the carpeting to the main box.

After battling with a generic harness, I tossed that in the trash and bought the Tekonsha. This unit comes with clear and easy to use directions. The entire installation took just over an hour on my Mini Countryman. The hardest part was crawling under the car to run the power wire from the fuse box. If you need a quick fix for hooking up a trailer, this unit is the way to go. The key difference between this and other non-powered universal adapters is that the module takes only the low voltage signal from the cars wiring to activate the module and then converts that into a 12 volt power signal to send to the 4-pole flat adapter. This makes the connection much more reliable and removes the additional burden on the existing system.

I needed to install a tow hitch and wiring harness on my performance Model 3. I chose a newer model Curt hitch for the towbar and this trailer harness as it was significantly cheaper here on Amazon then other websites that sold the Curt product. Installation was pretty simple. The hardest part was creating ramps for the car to elevate the back wheels enough to crawl under the car to run the positive wire all the way to the front terminal on the 12v battery. This was a bit tricky, however as I was already removing the entire bumper for the tow bar assembly... this too wasn't that difficult. You don't need the more expensive version with the fancier automatic clips that are short protected. This version is over $100 less and functions just fine so long as you pay close attention to the wiring colors coming from the Tesla. I followed a video tutorial for the more expensive product at eTrailer.com and was able to install this in just over an hour. Works just fine with no problems.

Easy to install I took my time to make it a professional looking job. Removed door kick trim followed all the wires. Pushed threw rubber boot on fire wall behind the battery. Very happy 👍

I had this installed on my Audi Q7 and it works well. Be sure to watch the installation video before you start.

Great product for great value. Installed it on my GLK350 Merc. with great help from e-trailer website video. Came out perfect. Other sites sell the same product but much higher prices.