For Tamiya Trucks:
A small plate to insert a switch , a small 3 mm LED and a potentiometer (Servonaut SM7).
The plate is mounted in the box on the right side of the truck where the MFC control panel is supposed to be mounted.
Potentiometer used :
https://www.servonaut.de/shop/de/product_info.php?info=p531_poti5k.html
Switch used :
https://www.bmr.co/fr/actuant-interrupteur-economique-016-1082.html?qs=interrupteur