I was missing volume controls near the steering wheel in my Dacia Spring. The buttons above the screen were too inconvenient to reach while driving.

Through springforum.de, I found a solution: a controller from a Renault Kangoo (around €10) works as well when using the correct connectors. However, several users mentioned that the controller is quite small and not easy to operate with your fingers.

To solve that, I decided to design an adapter.

I work in healthcare and don’t have an engineering background, so the design is fairly simple, but it gets the job done. I scanned the steering column cover using an iPhone 15 Pro, which gave me a reasonably accurate shape. Due to my limited experience, I wasn’t able to recreate this easily using simple geometry. If you want to use a different controller (as multiple options seem to work according to the forum),
I’ve also included the base cover so you can position another controller on the left side instead.

Printed in PLA with 100% infill for strength. You’ll still need to add two bolts and route the cable through the part.

In hindsight, it would have been smarter to design and mount the adapter first, and only then install the connector. I ended up having to cut the cable and solder it back together afterward.