Mounting Cage for Carrera Slot Car Controller Box

The Carrera digital slot car controller extension box does not include mounting provisions.  I am referring to part number 30348 which allows an extra two controllers to be connected so the race track can support six racers.  This model being shared is a simple cage with tabs to allow the extension box to be fastened to something so it doesn't move about.  It's a tight fit but the box can be popped into it.  I printed it with tree supports to hold the angled parts.