On this page of the guide to Car Mechanic Simulator 2021, we explain how to make your own music available in the game. Here's the instruction showing you where to upload your music to be able to listen to it on the in-game U-Zer Radio No. 1.
The PC version of the game enables you to create your own play list and play it directly in the workshop by selecting the radio station U-Zer Radio no. 1. To do this, upload your music files in .MP3 or.Ogg format to the right folder.
In the Steam app, go to the library and right-click on the game Car Mechanic Simulator 2021. Then select Browse Local Files.
Windows Explorer will display the contents of the main folder, Car Mechanic Simulator 2021_data. From there, proceed to the following folders:
'StreamingAssets,' then 'Music,' and then 'User.'
Paste your files in .MP3 or .Ogg format into this last folder. After launching the game, you will already be able to enjoy your own playlist.