One of the most distinctive features of the '65 Mustang fastback is the functional ventilation louvers found on the upper section of the quarter-panels. The elaborate devices looked fantastic, were fully functional, and could be opened or closed from the inside to ventilate the cabin as desired. The louvers were a complicated assembly consisting of a cast frame with individual inserts, each with its own decorative grille work. The next Mustang incarnation in '67-'68 still had an ornamental grille here, but it was far diminished in size and looked a little like an afterthought when compared to the ornate and integrated design of the original '65-'66 louvers.
The SilverHorse Racing Quarter...
The SilverHorse Racing Quarter Louver kit comes with complete and well-written instructions. This kit we pulled off the shelf is shown unpainted, but it can be finished in the correct factory color of your choice. Also seen at the left is the optional window removal kit, and at the right are the optional 3M urethane sealer and a small bottle of adhesion promoter. Installing the kit without the adhesion promoter and using sealer alone is not recommended.
In the Shelby GT350 for '66, these louvers were removed to save weight and improve blind spot visibility. The GT350 quarter-window treatment also happened to look great, and many enthusiasts with garden-variety Mustang fastbacks began to install these quarter-windows, which you could have purchased from Shelby over the counter. Now that the S197 cars come stock with the Shelby-style quarter-windows, it's a little ironic that one of the most popular modifications to the new coupe is the addition of the original '65-style louvers (or covering them with a Shelby-esque stick-on scoop -Ed.).
We have to confess that we do like both schools of thought here. However, the original factory effort on the '65 fastback was so attractive that we can see why S197 owners might want them to make their car a little different from the rest. This is where the folks at SilverHorse Racing come in. They now offer a conversion kit to give your '05-and-up Mustang coupe the look of the original '65 2+2. One advantage of the SilverHorse Racing kit is that even though the car has the look of the original-style louvers on the outside, rear quarter visibility is still possible because the inset area is clear instead of being a functional vent with grille work. In effect, you get the best of both worlds-classic retro looks while retaining your rearward visibility. Best of all, you aren't blocking off the whole window with a scoop.
After touring SilverHorse Racing's facility we travelled down the street to Trick Pro Motorsports in Melbourne, Florida, so its competent crew could show us all how to get the classic louvered look for your S197 Mustang. The unpainted kit is PN S197-300 and costs $159. The kits are available already painted in the factory color of your choice for $334. A window removal kit is available from SilverHorse for $36.95 as well as the urethane sealer and adhesion promoter for $12.95.

Here's the landscape inside...

Here's the landscape inside the rear of our car prior to installation. There are several things you'll need to remove, but the procedure isn't difficult. Notice the original glass window's field of view as well.

The first thing to do is to...

The first thing to do is to remove the rear seat lower cushion. Do so by pressing forward on the two retention clips underneath the seat cushion with a small screwdriver. You can carefully find them at the edge of the cushion when looking at eye level. When depressed far enough, the seat can be raised and removed easily.

Next, remove the doorsill...

Next, remove the doorsill plate on each side of the car. There are two retaining clips as well as double-sided tape for each one.

Underneath the back window,...

Underneath the back window, disconnect the rear window defroster wiring and remove the rear coat hooks using a T-20 Torx bit.

After prying off the trim...

After prying off the trim cap on the seatbelt D-ring, use a 14mm socket to remove the seatbelt pivot bolt. Repeat for the passenger side as well.

Fold down the rear seats to...

Fold down the rear seats to expose the push-pin clips holding the interior quarter-panels in place. The two plastic retainers, per side, can be removed with a standard trim panel removal tool.

To remove the lower quarter-panels...

To remove the lower quarter-panels from the car, carefully pull them forward, being mindful of the seatbelt as it passes behind each panel. Then, carefully slide the panels off of the weld seam.

The roof rail trim will need...

The roof rail trim will need to be pried down a little at the rear on both sides to free the upper quarter trim panels before they can be removed to access the quarter glass.

Moving to the outside of the...

Moving to the outside of the car, the first step is to install a double layer of good-quality painter's tape to protect the paint around the window edges during glass removal.

Turning to our window glass...

Turning to our window glass removal kit, we install the cutting wire onto the insertion tool with a sharp bend about 3/8 inch from the wire end. This will give the wire something to grab hold of while it's being fed underneath the quarter-window glass, through the sealer, and out to the exterior if the car.

Now the wire is fed under...

Now the wire is fed under the glass using the tool. The wire is turned 90 degrees so that its bent portion reaches the exterior.

It would really be nice not...

It would really be nice not to scratch the paint, so great care is used in keeping the wire away from the body as it comes out from underneath the glass.

Once the wire is retrieved,...

Once the wire is retrieved, it is attached to this stout metal pull handle as shown. The cutting of the factory sealer is a two-person job, with one inside the car and the other outside, like a two-person team cutting a tree.

The outside person carefully...

The outside person carefully draws the wire around the edge of the glass, with the inside helper following along. It's the job of the outside person to keep the cutting wire away from the paint.

As the factory sealer is cut,...

As the factory sealer is cut, the glass panel will begin to loosen. A third person is a nice thought here to keep the glass still and prevent it from falling out of the car. Large strips of painter's tape across the glass will also work as a third hand in a pinch. Repeat these last few steps to free the other quarter-window.

Now the opening is prepared...

Now the opening is prepared for the new part by removing most, but not all, of the old adhesive sealer. Some of the old material is left to help with adhesion. Once the louvers are in place, they will sit just beneath the edge of the body panel as the original windows did from the factory. While adding extra sealer to move the louvers flush to the body is possible, it is not recommended as it increases the chances of wind noise or water leakage.

Prepare the new louvers by...

Prepare the new louvers by scuffing their mating surfaces, being careful not to damage the paint on the edge. Next, apply an even coat of the adhesive promoter to the edge of the louvers, again being careful not to get any on the painted surfaces. Use of the adhesion promoter is mandatory, as the louvers' seal will fail, causing the louvers to come loose and pop out when the doors are closed with the windows up or when driving with the windows down.

Cut the opening of the adhesive...

Cut the opening of the adhesive sealer tube into a small V-shape as shown. This will ensure a bead that is narrow enough when the material is applied.

Here, our technician applies...

Here, our technician applies a generous and uniform bead of adhesive sealer to the perimeter of the window openings.

Next, the louvers are carefully...

Next, the louvers are carefully put into place and held with tape to prevent the parts from sagging while the adhesive sets up. The new part should be flush with or slightly recessed from the body surface. According to SilverHorse Racing, a 0.110-inch gap at the bottom of the insert is desired.

Here's a view of our installation...

Here's a view of our installation from the inside of the car. It's easy to see that the original view to the rear is still quite visible, even when looking straight through. When looking from the driver's seat back, the louvered window opening has almost no loss of visibility to the rear. The instructions call for at least eight hours of drying time. During that time, it is imperative that the car doors not be closed abruptly with the side windows up. This could easily move the insert and break the seal. Once the adhesive has set for the required time, you can drive the car to check for wind noise and you may wish to test for water leaks with a garden hose. Once satisfied that there are no leaks, carefully reassemble the interior and enjoy your Mustang's great new looks.