I got the Ecto for christmas and I felt the urge to squeeze in some remote controlled Motors.
The new Powered Up have just the thing (although they are badly documented)
One month after christmas I had it up and running. Tell me what you think.

    • quasi invisible
    • minimal invasive - all gadgets work
    • Battery replacement with no dissambling
    • light and sound kit still fits in
    • Lego POWERED UP Bluetooth Remote Control
    • no discontinued Power Functions
    • complete Instructions on rebrickable

I made my first video about that:  

For this motorization I used LEGO's Powered Up Large Technic Motor for steering. That thing is just made to be used for the steering. It can act like a servo, because it has an internal position sensor. It is slim and dark bluish gray so it replaces that kardan drive below the front seat perfectly.

Aditionally I didn't want to take it appart every time I change the batteries, so you can reacht it from the bottom.