Installation Time: Afternoon
June 10, 2016
Great Looking Rear Window Louver
I added a spoiler, side scoops and quarter window louvers on my '14 coupe, and now decided to add a rear window louver. American Muscle sells three, "Rear Window Louvers - Textured ABS (05-14 All)," item number 75000; "MMD ABS Rear Window Louvers (05-14 All)," number 41336; and "Willpak Rear Window Louvers - Smooth Aluminum (05-14) All," number 75002. The first two are priced about the same, but 75000 has a rounded look, whereas 41336 has stair steps. Item 75002 also has a stepped look, but is more expensive. I preferred the rounded look and ordered 75000.
One of AM's benefits is its buyer reviews, and I read how others resolved issues with my louver. This unit is attached to the glass with six hold down plates that are taped using promoter, but the louver is removable for cleaning. These plates will need their edges sealed with silicone, so I used the clear version. You will also need masking tape.
Several reviewers noted that the louver's top center may bow in the heat. Some added heavy duty Velcro, but others contacted AM or Willpak Industries, the manufacturer, and added one or two extra brackets to prevent bowing and better secure the louver.
I called AM's Customer Service at 1-888-332-7930 to request more brackets. This louver comes with six, and AM contacted Willpak who sent another six at no charge. (Willpak is in Canada and may be reached at 1-888-945-5725.) This set included plastic hold down nuts, so I now have spares, along with more promoter. I added two more brackets to my louver's top. There were two spaced about 27" apart, so I drilled two holes with about 9" gaps. I then removed some weather stripping from the louver, and then had eight plates holding my louver.
The instructions were straightforward. Keeping the attaching areas for the plates free of dust was important requiring repeated cleaning. Willpak said to attach the plates to the louver and lay it on the glass to check the fit. Be sure the unit sat high so that the trunk opens, so open your trunk and check at each step of the installation. Then mark the hardware's mounting locations and remove the louver. They said to remove the backing tape and apply the louver to the glass, and then remove the louver leaving the hardware attached to the glass, and press the brackets for a good seal.
I thought this method was risky and made changes as I was installing my louver alone. You only have one shot at sticking the louver on the glass, and it is not easy to position in one motion. Instead, I added the brackets to my louver, placed it on the glass, marked the positions of the bolts with masking tape, and removed the louver and brackets. I then applied masking tape on the glass, measured where each bolt was, taped the plates temporarily on the glass, and test fit my louver. When satisfied that my plates were positioned correctly, I removed them, added promoter to the glass, let that set up, and attached the plates. Then I knew everything fit properly.
Willpak also recommends removing the louver before severe winter weather. Realizing that my eight exposed metal brackets would look awful on the black edges of my glass, I sprayed them gloss black before attaching. If my louver is removed, my rear glass looks normal.
The final step is adding a thin bead of silicone to the edges of the plates so that moisture cannot undercut the tape, and then squeegee with your fingers. Be patient as silicone easily gets on the glass and should be carefully wiped with a soft rag. Then leave the louver off your Mustang for 24 hours, preferably out in the sun, to allow the bond to cure.
Then check that the plates bonded correctly to the glass and add the louver. I had to enlargen my top four holes slightly to add my louver as the fit was tight. I then test drove my Mustang up through 70mph and the louver was quiet, although you can see the middle of the louver buffeting slightly through your rear window.
The result is a great looking window louver complimenting my other trim pieces. It may be removed for cleaning the glass or storage as the nuts are easily removed. The visibility through my rear window is reduced, but acceptable. Overall, I am in favor of anything that makes my '14 look more like that '68 Mustang I never owned, and this excellent modification does that!
Rick Mitchell, Catonsville Mustang Club