Hyundai Kona N Rear Diffuser Fin Extenders (Clip-On | No Drilling)

Upgrade the aggressive look of your Hyundai Kona N rear diffuser with these custom clip-on fin extenders. The parts are designed to slide into place from the side and lock onto the diffuser using an integrated clip system, allowing installation without drilling or permanent modification to the vehicle.

This project started as a fun modeling challenge after a Kona N community member asked if anyone had created fin extenders. It became a great opportunity to practice automotive modeling using scan-based geometry and reference surfaces to match the shape of the diffuser.

Design Concept

These fin extenders were designed to enhance the factory rear diffuser by extending the visual length and sharpness of the diffuser fins while still maintaining a shape that flows naturally with the Kona N's rear bumper lines.

The goal was to create a part that:

• Looks like a natural extension of the OEM diffuser

• Is printable on consumer 3D printers

• Can install without drilling or permanent modification

• Allows sanding and finishing for an OEM-style appearance

The geometry was modeled to follow the diffuser contours while maintaining structural thickness suitable for 3D printing and post-processing.

Clip-On Mounting System

A key feature of this design is the integrated slide-in clip mechanism.

The part is installed by sliding in from the side of the diffuser fin, where the clip geometry locks onto the diffuser using tension.

The mounting system includes:

• Lower hook that captures the underside of the diffuser

• Upper tension clip that presses inward to secure the part

• Tapered leading edge that helps guide the part during installation

Because of this design, the fin extender can hold itself in place without glue or screws.

For additional security (especially at highway speeds), users may optionally add automotive-grade double-sided tape such as 3M VHB inside the clip area.

No drilling or permanent modification to the car is required.

Recommended Print Settings

Since these parts are mounted externally on the vehicle and exposed to heat, sunlight, and weather, PETG is recommended over PLA.

Suggested print settings:

Material: PETG

Layer Height: 0.16 – 0.20 mm

Infill: 30% Gyroid

Walls: 4–5 perimeters

Top/Bottom Layers: 5–7

Supports: Only where required, depending on orientation

Bed Adhesion: Brim recommended

These settings provide strong walls and enough outer thickness for sanding and finishing.

For users with enclosed printers, ASA is also an excellent option due to its improved UV and heat resistance.

Post Processing (Optional)

For the best appearance:

1. Lightly sand the printed surface

2. Apply filler primer

3. Sand again if needed

4. Paint and clear coat

This can produce a finish similar to OEM plastic trim pieces.

Installation

1. Align the fin extender with the diffuser fin.

2. Slide the part in from the side of the diffuser.

3. Allow the lower hook and upper tension clip to engage.

4. Press gently until the part sits flush.

Optional: Apply 3M VHB tape inside the clip area for additional security.

Because printer tolerances and materials vary, minor sanding or adjustment may be required for perfect fitment.

Printer Compatibility

Files available for:

• Creality K2 Plus

• Creality Hi

Other printers with similar build volumes should also work.

License

This design is released under the Creative Commons CC BY-NC-SA 4.0 license.

You are free to download, print, and modify the design for personal use, but commercial use is not permitted without permission.

If you are interested in producing or selling this design commercially, please contact SnapFit Labs.

Credits

Hyundai Kona N Rear Diffuser Fin Extenders

0.2mm layer, 4 walls, 30% infill