These kinds of body mods are not for the emo kids, these mods won’t require you to wear a bandaid on your lip when you go to work at the local pizza joint. And these body mods actually look good. The latest generation of Mustang is great looking by itself, but most Mustang owners like to personalize their pony’s to express themselves, much like the maligned emo kids (depending on your age, you may want to think goth, stoner, or greaser). With so many choices in brands and styles, even at a Mustang-only show it’s pretty easy to find 20 different spoilers on 20 cars.
This Mustang is getting a facelift, courtesy MRT (Mustang Racing Technologies). To update the look of the GT, we added an “aggressive” chin spoiler, “aggressive” ducktail rear spoiler, and rear window louvers. The changes are subtle, but effective, as the louvers really lower the look of the roof line and the chin spoiler stretches out the nose just enough.
The installation of these parts varies from no-brainer to complex. Which ones are which might actually surprise you. In this case, the easiest mod was the chin spoiler. We had it installed in about 10 minutes with just a screwdriver. The most difficult part was the spoiler, which was a bit surprising. What made it more challenging was the fact that the factory spoiler left two holes in the rear deck that the new spoiler did not cover, we had to weld them up. If your Mustang did not have a factory spoiler, then no worries. The rear window louvers were almost as simple as the chin spoiler, but the amount of small parts and procedures made it take longer. The louver kit we used features hinges and prop rods, making it easy to clean the back window. Once installed, these parts change the curb appeal of this Mustang.
All told, we had the entire task completed in about 3 hours. This does not include painting. Since the ’05 we are working with already had custom flat-black paint above the beltline, and the parts come in flat black, the only ones we have to deal with are the chin spoiler. The factory bumper had been smacked a few weeks before this build was scheduled, so we had to replace it with a new one, which is black as well. In most cases, you should install the parts, and then remove them to have them painted unless you want to paint the entire car.
01. We started with the spoiler, since we figured the holes may be an issue, and we were right.
02. The factory spoiler is held in place with four studs, two on each end. A 10mm socket makes quick work of that. The spoiler is also held in place by some double-sided tape, so you have to be careful prying the spoiler up or you could crease the trunk lid.
03. The new spoiler looked like it would cover the rear-most hole (it didn’t), so we focused on the front holes.
04. A copper bar was placed on the underside. Welding wire won’t stick to the copper, so this trick works great for filling holes.
05. You want to use short bursts when welding up the holes. The thin sheet metal will warp quickly. Once the metal cools, we ground it down with a die-grinder.
06. Then some body filler was mixed up and spread onto the deck lid. There is a magic point for sanding body filler, called the green stage. On a small repair like this, it is less of an issue, but if you need to do a lot of sanding, it helps. The green stage is when the filler is no longer tacky, but not fully cured. It sands really fast in the green stage.
07. Once cured, the filler was finish sanded with a DA sander and some 200-grit.
08. The new spoiler from MRT has pointed studs. This is particularly helpful in setting the drill points. Once positioned, pressure above the studs will mark the deck lid.
09. Using a ¼” drill bit, the deck lid was drilled for the new spoiler. On the underside, we had to open up the holes to accommodate the nuts as the studs are not long enough to reach all the way through both sides.
10. There are some alignment features to match up to the deck lid. There is a little room for error here, but not much.
11. Unfortunately, the new spoiler did not cover the rear holes, so we had to do it all over again.
12. The chin spoiler was the easiest of all the mods we made. This piece adds an aggressive note to the factory bumper cover. The bulk of the spoiler is held in place with double-sided tape.
13. The sections where the spoiler and the bumper cover meet and are bonded by the double-sided tape.
14. Then those same sections were wiped with alcohol, allowed to dry, and then wiped with the included adhesion promoter. This stuff take about 60-seconds to dry and the part needs to be installed within 1 hour of application.
15. We installed the 3M tape and checked the fit to the bumper while we had it off the car. You don’t need to remove the front bumper from the car, but we were replacing it anyway.
16. Using these factory screw locations on the inner fender wells, one side of the spoiler was mounted using the factory screws.
17. Then the covering was removed from the tape and the spoiler wrapped around the factory bumper and pressed in place. It takes 60 seconds to get a good bond, and you need to apply even, direct pressure to the taped area. If you have painted this part, you need to be careful about flexing it, which can crack the paint.
18. With the tape secured, the other side was screwed to the other inner fender. This really changes the front end. It would also create a nice contrast if left black on a painted bumper.
19. The window louvers came with a paper guide that gets taped to the rear window. The initial position is based of measuring to the center of the rear window. We wiped the glass in the hinge-mount area with alcohol, then adhesion promoter.
20. The hinge mounts were placed on the window and pressed in with the handle of a screwdriver. You want to make sure to cover the entire hinge to get a good seal.
21. The retainer clamps have to be assembled onto the louvers. These actually take a little adjustment to get the set down just right.
22. The prop rods install with the same 3M tape. Make sure you use the alcohol pads and adhesion promoter.
23. You need a buddy to help set the louvers to the car. The edges of the louvers get lined with a little foam tape to protect it from scratching the glass.
24. The lower retaining pads were marked for position on the window with masking tape, then the window was cleaned with alcohol and prepped with the adhesion promoter. Then the pads can be installed to the glass.
25. The upper retainer clips install on the outer edges of the louvers to keep them from lifting at speed. That would be bad.
26. The rear spoiler and louvers look great. All the car needs now is some new wheels and it will be set.
A life-long gearhead, Street Tech Magazine founder and editor Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 5 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced. You can follow Jefferson on Facebook (Jefferson Bryant), Twitter (71Buickfreak), and YouTube (RedDirtRodz).