Close but no seagulls up there..................

It is probably a radar dome and the other end has a skylight view port maybe a mobile UFO hunter rather like the storm chasers you see on TV.
Either that or he has perfected the first mobile pressurised water reactor small enough to fit in an eriba and is using it to go off grid.
Would explain why the skylight and windows are open at that altitude......... to let the heat from the reactor out.

Where do you think the flux capacitor is fitted?

By the way that's not the first Eriba with a satellite dome I've seen.
One turned up at Derek's first Wareham mini meet a few years ago and again at the Bodensee Eriba Eurofest. it was on a Puck giving it a passable submarine conning tower look.

Perhaps they're just very short and don't need an elevating roof?

I should've gone to specsavers

You're all wrong, it's clearly over the trampoline so that you don't hit your head whilst bouncing.
Simples!

[quote="Randa france"|p24800[
The mind boggles ........... [/quote]

...as do all the other body parts!

Yes remember that Tony, did anyone get his handle?