Not happy with "cadillac" sounding horns in the GTS, I opted for something a little more retro. Original 911 horns to me sound the best and easily fit in the area between the bumper support and the front trunk just below the original mounting points. In fact , there are 2 factory unused threaded studs just waiting to be used. I also used VW Audi adaptor to plug into the existing wiring without cutting anything. The adaptor wasn't the perfect fit, but worked nonetheless.

Parts needed:
1 Porsche 911 high tone horn 911-635-101-21 $70
1 Porsche 911 low tone horn 911-635-102-21 $80
2 Porsche 964 mounting brackets 964-635-113-00 $27
2 VW Audi 1J0973802 2 Pin plug $20
miscellaneous , connectors, heat shrink $ 5
Total $ 202.00 not including shipping or tax

I am sure you could do this cheaper, by purchasing used horns and making the brackets. I opted to buy new...


First step is to undo the front bumper without removing it entirely.








Adaptor to plug into original horn plug add 2 soldered connectors and heat shrink


I painted the Trumpets red to further the retro look. Not original MIXO's but look pretty good.







You can see I used the factory 964 mounting bracket. The bracket is attached to the 8mm stud in firewall


Here's how it sounds and I can go back to the original any time

 

Great job, Steve! I'll be listening for you on the road.

 

That sounds really good. One of my horns is out, coincidentally. Hmmmm

 

Why spend time and money on a horn I (almost) never use?? Oh well, I'm glad you're happy with the results.

 

That is totally mad crazy and I think you are way cool for doing it!!! Congrats.

 

If you ever driven in LA.traffic.....you'd use the horn on a regular basis. A lot of oblivious drivers here

 

Have you ever driven in NYC? For example, when the light turns green, if the driver in front is not moving in less than a millisecond the horns behind him blow (and not just a quick toot). Another reason I don't miss living in the metro NYC area.

At least the horns installed by the OP have a reasonably pleasant tone.

 

White GTS on silver five-lug wheels...yum. Man, is that thing a looker in your avatar.

Love the horn mod, too!