Best way to fit origin B2 in a MINI ?

[wiz 1]

Looking at buying a scamera detector probably the Origin B2 as I've heard good things about it. Would prefer the solo as I change cars quite a lot but got one problem - Heated windscreen, so the gps Aeriel has to go in the back only place I can think of putting it is in the rear side window but don't know if I'll get a good signal. The back might be awkward with the boot opening. Any one got any ideas ?