DIY: Shark Fin Antenna for SiriusXM - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Hi all, first DIY so be gentle on me. When I knew I was going to replace my fartory radio in my 986 I knew I wanted SiriusXM as an option, but knowing how ugly the antenna that comes with the SiriusXM SXV300 install kit is, I wanted something different and much more in tune with today's look. So, I went looking for a shark fin antenna that I though would compliment the lines of our cars. I settled on this one; Since I already had the Sirius SXV300 kit, first thing to do was to get rid of the guts in the new shark fin antenna and prep it for the Sirius antenna. Most of the shark fin antenna I looked at have a small "shelf", so the first thing I did was drill a small hole for a screw. (this step is optional if you want to rely on just the 3M tape to hold it in place) Here is the fin with the screw in place, a small amount of epoxy on the back side to hold it in place is all that is needed; Now onto the antenna guts. First thing you need to do is disassemble the SXV300 antenna. This done by removing the decal on the backside and removing the 4 tiny screws that hold the back on. They are very tight and you may have to drill them out, I had to drill 2 of mine. Once they are out you can remove the guts. You can now see the rare earth magnet plate and the electronics, we only need the electronics. The fin antenna I bought has a nice semi-flat are that is very accommodating for placement of the electronics and I used epoxy to secure the antenna to the fin, but you could probably use RTV, hot glue gun or silicone, I choose epoxy. And while placement of the antenna is not critical, it IS important that you place it with the antenna facing upwards, otherwise you may never receive signal. You are now ready to install the shark fin. I originally wanted to install my fin dead center or the rear cowl, however after discovering that there is quite a lot of support structure on the underside of the cowl, I ended up having to move it forward about an inch closer to the top. First thing I did was locate the centerline of the cowl, which was easy since Porsche actually did the work for me. If you look closely, in the third brake light there are marking lines in the lens that you use to find center, the space between the part number and the "Made in Germany" is the center of the light. The next step is only required if you actually are using the mounting screw installed in step 1. Once you have defined centerline, place the cowl in service mode and remove the rubber hockey puck looking piece on the underside of the cowl, it's glued on so just carefully pull it off, we will be reusing it. Now here is where it gets scary, you are going to be drilling either 1 or two holes depending if you are using a mounting screw, I did, so two holes are required. First hole is 1/4" for the mounting screw, the other hole is 1/2" for the antenna wire and rubber grommet that the wire is fed through. If you are using the mounting screw, pre-drill a small hole in the rubber hockey puck location about 3/8" from the back edge, the edge closest to you from the bottom. I started with a 3/32" hole as a pilot hole, then finish with a 1/4" hole from the top. This is for the mounting screw. Now drill a 1/2" hole about 3 1/2" from this hole, this is for the rubber grommet, (important!), this is where the antenna wire will be fed through. Once this is done, check placement of the fin antenna, clean the area thoroughly with rubbing alcohol, remove the 3M protective film and place the fin antenna on the cowl. You pretty much get one shot at this so ensure your alignment is correct. Now install the nut for the mounting screw with a drop of blue locktite, if you are using an nylock nut you can skip this. The fin is installed at this point. RTV the rubber hockey puck back in place, route the antenna wire to which ever location best suits you, connect it to the SXV300 receiver and your radio, enjoy the SiriusXM entertainment! Finished pics in next post.

An alternate approach? https://cai-store.com/collections/frontpage/products/premium-satellite-antenna-mount-for-911-cayman-boxster