What is that black material you're putting the LEDs in. I know they sell premade ones for certain cars but can you just buy that material and shape and sell it yourself?
I believe that that's some form of acrylic? 🤔 I saw another dude had some of those panels 3D printed where he then had the LEDs slot into, works exactly the same. In my case I'm working on a complete custom design for my Mk1 Golf, so I'll be 3D printing the whole housing with various slots for the different types of LEDs I'll be using as I'll be incorporating strips as well, so 3D printing defs is an option. I'd suggest something more heat resistant and durable than PLA tho, either PETG or even ABS. I'm still new to 3D printing tho, so I'm still learning too