DIY – Side Splitters – Alternative to Mopar Side Skirts – Side Diffuser How-to Install

I bought a universal side lip a few months back – it doesn’t really fit the Dart, but I made it work. It had the side wing on it already, so it trumped my idea to match the front splitter wings, as shown in my DIY aggressive front splitter wiki article. I had a hard time getting a hold of it, as it was backordered, and I ended up waiting months for it. It came with some mounting hardware, but didn’t quite work, out of the box and a plug-and-play. First step was to mock it up to the car, and figure out a plan.


My first hurdle was fitting to the front Mopar mud flaps. The angle of the flaps made it difficult to match this up. I tried a few things, but ended up trading the mudflaps for the Rally Armor ones, made for the dart. It fit the aggressive style a bit better. I ended up somewhat selling the Mopar mudflaps.

Here are the (flatter) Rally Armor front mud flaps:

After I pulled off the EZ Lip, I found there were multiple plugged holes under the body. I found plastic inserts to catch a screw and attach to the holes. Found them on ebay, they clicked in, then pre-drilled the holes to line them up. This was easy b/c they were much wider, so it had some play.

I could click them in and rotate 90 degrees to lock them in:

I had to drill the holes, and then cut out a small square from the splitter, in order for it to sit flush with the side of the ride:
Then I applied adhesive promotor (after thoroughly cleaning the surface with acetone) and applied the double-sided adhesive:[

(I later figured out, it was quicker and easier to use self tapping screws, through the holes on the metal mounting bracket. This eliminates the need for extra holes in the product.)

Once I had the positioning perfect, I marked my cuts to angle the front of the lip. IMO, it was the only solid way to link the two together cosmetically. Any other way I tried, looked sloppy. This follows the lines of the car better, and solves the issue of matching the seams on a curved edge.

I did this project on a 90 degree day, and I realized these may sag a little bit. They wouldn’t come loose, but I wanted to make sure they were completely rigid. I took 2 long metal brackets, used for shelf supports, and fitted it underneath the lip. I used self-tapping screws to secure the metal support, as well as the fastened side splitters. I can say, the car has been well over 100 MPH several times since the installation, as well as several hundred highway miles without an issue.

Finally, I used this carbon fiber-looking trim for underneath the front diffuser. I tried it on the sides originally, but it looked so good on the front.

Here, you can see the front and side splitters, as well as how the Rally Armor mudflaps look. I’m lowered, and I may raise the rear mudflaps, just a bit.