Upgrading the rear of an S550 Mustang is one of the easiest ways to give the car a fresh, modern look, and swapping in a set of Ford Mustang sequential LED tail lights delivers a big visual payoff for a relatively small amount of work. We recently followed along with the process on a 2018 Ford Mustang using tail lights from Form Lighting, and we were impressed by how straightforward the whole job was. In this guide, we will walk you through everything we saw, from popping off the trunk access panel to transferring over a factory plastic panel and buttoning the new lamps back into place.

If you have ever wanted to give your Mustang a custom rear appearance without cutting, splicing, or fighting with error codes, this is the kind of install that makes it happen. The demonstration was performed on a 2018 model, and the process is representative of the 2015 and up Mustang generation. Below, we break down each step and highlight the features that make these lamps worth considering.

Why We Like Sequential LED Tail Lights on the S550 Mustang

The factory Mustang tail lights already come with a sequential turn signal look, so it is fitting that the aftermarket upgrades keep that signature animation. The Form Lighting units bring sequential turn signals, a clean red running light, and error-free operation, which means you get the custom appearance without triggering bulb-out warnings on your dash. That error-free behavior is a big deal, because nobody wants to see a warning light every time they flick a blinker. These lamps are also offered in three lens finishes: red, smoked, or clear. Each option changes the character of the rear end. The red keeps things classic and OEM-plus, the smoked adds a stealthy, aggressive vibe, and the clear gives a crisp, modern contrast. Whichever you pick, the performance stays the same. You can browse the full set of options for the Sequential LED Tail Lights for the S550 Mustang if you want to compare the finishes side by side before ordering.

Tools and Prep Before You Start

One of the reasons we like this install is that it does not require any specialty tools. You will want a 10-millimeter wrench or a 10-millimeter deep socket to handle the three nuts that hold each tail light in place, plus some basic hand tools to deal with the trunk panel hand knobs and the plastic clip on the carpet liner. That is really the extent of it. There is no wire cutting and no soldering involved, which keeps the job clean and beginner friendly. Before you dig in, open the trunk and give yourself some working room. You will be accessing the tail lights from inside the trunk cavity, so having the space cleared out makes the process go faster. Once you are set up, the whole job moves along quickly.

Step by Step Mustang Tail Light Install

Here is the full walkthrough as demonstrated by Jordan from Form Lighting. We are covering one side, and then you simply repeat the same process on the opposite side of the vehicle.

Step 1: Remove the Trunk Access Panel

With the trunk open, the first step is removing the plastic panel that gives you access to the back of the tail light. This panel is secured by four hand knobs, two on each side. You can twist these off by hand, no tools required. Set them aside somewhere safe so you can reinstall them later.

Step 2: Remove the Carpet Liner Clip

Next, remove the plastic clip on the side of the trunk that holds the carpet liner in place. With that clip out, you can pull the plastic trim panel and peel back the carpet trunk liner to expose the hardware behind the tail light. Take your time here so you do not stress the carpet or the trim.

Step 3: Remove the Three 10-Millimeter Nuts

With the trunk liner pulled back, you can now see the three 10-millimeter nuts holding the tail light in place. Remove these using either a 10-millimeter wrench or a 10-millimeter deep socket, whichever you find easier to fit in the space. These three nuts are the only fasteners holding the lamp to the body, so once they are out, the tail light is nearly free.

Step 4: Disconnect the Wiring Harness

Before you pull the lamp completely off the vehicle, disconnect the wiring harness. This is an important step because you do not want to yank the lamp away while it is still connected. Once the harness is unplugged, you can pull the tail light off the vehicle and bring it to a bench or a clean spot to prep for the transfer step.

Step 5: Transfer the Plastic Panel

Before setting the stock lamp aside, you will need to remove a plastic panel from the factory tail light to transfer it over to your new Form tail lamp. This panel is only held on by a few clips. All you need to do is pull outward and it should come right off. Move it over to the new lamp so everything lines up correctly during reinstallation. This is the one part-swap step in the entire install, and it takes just a moment.

Step 6: Install the New Lamp and Repeat

Now you can install the new lamp on the vehicle by reversing the same steps you used to remove the stock lamp. Reconnect the wiring harness, seat the lamp against the body, and thread the three 10-millimeter nuts back into place. Once the first side is done, repeat the same process for the other side of the vehicle. After both lamps are mounted, put everything back together, the carpet liner, the trim panel clip, and the four hand knobs, using the same steps you used to take it apart. As Jordan noted, with very little effort your new Form tail lights are installed. Whether you went with the red, smoked, or clear tail lights, you now have a new custom look that helps your Mustang stand out, along with the same sequential turn signals, clean red running light, and error-free operation.

Tips We Picked Up During the Install

A few things stood out to us as we followed this install. First, keep track of your hardware. The four hand knobs, the plastic clip, and the three nuts per side are all small pieces that are easy to misplace on a busy garage floor. A small parts tray keeps everything organized. Second, be gentle with the carpet liner and trim panel. These plastic pieces flex, but you still want to work them free carefully so you do not crack a clip or crease the carpet. Third, double check that the transferred plastic panel is fully seated on the new lamp before you mount it. Since it clips on and off easily, it is worth confirming it is locked in place so it does not rattle later. Finally, when you reconnect the wiring harness, make sure the connector fully clicks in. Because these lamps offer error-free operation, a solid connection means you get the clean plug-and-play behavior without warning lights on your dash.

Other Mustang Tail Light Options to Consider

The Form Lighting units are a great pick, but they are not the only game in town. If you like to compare before you buy, take a look at the Morimoto XB LED Tail Lamp Upgrade, which is another popular sequential option for this generation. You can also browse a broader Mustang Tail Light Upgrades collection to see how different brands approach the rear lighting on these cars. For more on what Form offers across the platform, the 2015-2023 Mustang Lighting Upgrades page is a good hub to explore. And if you own an older Mustang, we have covered the classic body style too. Check out our Fox Body Sequential Tail Light Install Guide for a look at how the sequential upgrade works on that generation.

Final Thoughts

This is one of the most approachable lighting upgrades you can do on an S550 Mustang. There is no wiring surgery, no drilling, and no software to mess with. You remove a trunk panel, pull back some carpet, take out three nuts, disconnect a harness, transfer one plastic panel, and bolt the new lamp in. Do it twice, put everything back together, and you are done. The result is a custom rear look with sequential turn signals and error-free operation, in your choice of red, smoked, or clear. For the effort involved, it is hard to beat the return on a set of Form Lighting sequential LED tail lights.

Frequently Asked Questions

What years of Ford Mustang does this tail light install guide cover?

The video demonstrates the install on a 2018 Ford Mustang, with the process shown as applicable to the 2015 and up Mustang generation referenced in the title.

What tools are needed to install FORM Lighting Mustang tail lights?

You need a 10-millimeter wrench or deep socket to remove the three nuts holding the factory tail light in place, along with basic hand tools to remove the trunk panel clips and hand knobs.

Do I need to transfer any parts from my stock tail light to the new one?

Yes, the video shows removing a plastic panel held on by clips from the factory tail light and transferring it over to the new FORM tail lamp before installation.

What color options are available for these Mustang tail lights?

The tail lights are available in red, smoked, or clear lens options according to the video.

What features come with the FORM Mustang tail lights?

The tail lights include sequential turn signals, a clean red running light, and error-free operation as stated in the video.