[ALPHAFERT]

I used to pull a little trailer with my honda fit for things that wouldn't fit or were too messy to put inside. I wanted to do the same with my wrx so I purchased the hidden hitch (easy install & totally hidden) & the curt wiring harness. The hitch is on but I ran into some trouble with the wiring. For the main install you just insert the harnes between the tail light connection. You also need to supply 12v power. The instructions say to connect straight to the battery. Two things I am uncertain of. There is a fuse looking thing between the + terminal & the power to the car. Do I connect directly to the terminal or on the other side of that "fuse"(actually not sure what it is)? The second issue I ran into is how to pass the wire through the firewall. It looks like there are several spots I could use as well as a few rubber plugs I could puncture to pass through. My issue is that I don't want to rip out the dash.

Sorry if this is a repost or in the wrong place & thanks in advance for any input.

 

[gfenzil]

Can you post a pic? The hidenhitch website doesn't list WRX as an option. Which model did you get?

I am not looking to tow, but would like a bike rack. Thanks!

 

[rqjoe]

You can run a wire back to the trunk area from most any hot wire inside the car. Trailer lights should not draw much power and thus tapping off another circuit should work in most cases. I ran a wire from front passenger area down by where the right foot would be behind that small plastic panel there. There is a green/black hot wire there going into the front passenger door for the window or door lock. I then ran it along the side of the car under those long narrow floor panels, under the carpet/around the seat belt post and up along the side of the rear seat into the trunk. It works great for extra lighting on the rear of the car. This particular green/black wire is only hot when the ign switch is on.

 

[ALPHAFERT]

I didn't take a lot of pics but here is a link to where I got it. There is pretty good pics there. There is some recorecommended bumper cutting but none visible & its different than the instructions. You can skip cutting by not puting the 2 clips right by the hitch back.
https://torkliftcentral.com/2015-2017-subaru-wrx-wrx-sti-ecohitch-invisi

 

[ALPHAFERT]

Thanks much rqjoe!

 

[irickchad]

It's ill advised to tow ANYTHING on a WRX, even if it's just a "small trailer" due to possible damage to the AWD system. It states it specifically in the manual. Just FYI. Enjoy the car!

 

[ALPHAFERT]

Yeah, thats where I should know better than to trust people & looked up the manual before purchase. That was a requirement that I brought up with the salesman. Curious as to what the non-US manual says & what issues it may cause. With my fit towing was ok pretty much everywhere but the U.S. & the only real mechanical difference with most was .2liter smaller.

 

[rqjoe]

So first the disclaimer - if it says not to tow anything in the manual, doing so does indeed give you much less leg to stand on in any case of problems and warranty claims.

Now the reality of towing with a WRX. I could go into a very long dissertation on how and why doing some light towing with a WRX is probably OK, but I will do the short version here. If the hitch is well designed and you drive like a little old man when towing a light trailer you will be fine.

 

[irickchad]

You're driving a car where people have set entire differentials on fire from running a donut tire....so if you want to chance it, that's all you.

 

[ALPHAFERT]

Not to argue on this as I am not super knowledgeable about this but I feel like there is a difference between running a donut (smaller wheel making that tire rotate constantly at a different speed) and pulling a small trailer which adds more weight. I would actually like to know what is so different between the base wrx & like a forester or outback that you can get a hitch from the dealer.

 

[rqjoe]

So while I do not know as in knowing by reading Subaru design data, I can venture a good guess:
Subaru simply did not design the WRXs for a hitch. They did not put factory hitch attach points and thus probably did not do stress/fatigue analysis with a towed load (trailers.) And then it follows they did not test for towing. So now they are forced to say "do not tow" because of no design or test for it. They probably did all this for the other models.

But just because there was no design for the hitch, doesn't mean it won't work - it just means no one knows what the stress margins are - they may be fine for a light load.

 

[ALPHAFERT]

I finally finished. There was an unused grommet above the brake peddle. When done & reconnected the battery my driver side window auto feature & the passenger window from the drivers side didn't work. After pulling off a bunch of dash panels & trim pieces to make sure I didn't disconnect something I decided to check the manual. Turns out this is part of a feature & it gets stuck that way. You have to turn the car to on, lower passenger window 1/2 way, close it holding 1 sec past closed then all the way down. Then repeat for the drivers side. Heads up to any that disconnect the battery on a 17 wrx.