When I got my car, it was installed, so I have no idea what it looked before. The compartment is about 8 to 10 cm deep, totally closed and when I open the front cover over the batterie etc., you see nothing but the original panel sheet, so there must be some space between the dashboard and this panel sheet. there is a simple fastbutton to open and close.
and Nippymog, I have no immobilizer
I have the smaller tunnel with more room for my legs, on the site of morgan Park
Morgan Park Zubehör Threewheeler you see my blue Dreirad with both options

and this is my TomTom Rider installed in the small box on this modified tunnel:
