Sorry for the delay replying.
Putting it up single handed?
It can be done, though it is fiddly. My partner has MS so I normally do the lot myself, - every site I've been on has always had someone offer to support the middle when it's 'going up'. Once it's up the pegging etc is done by me.
Seats?
First time we went I had the seats folded - and spent every night worrying about raising my head and impaling it on the clamps and metal work!
Taking the seats out is really easy the single seat & the double seat are each attached simply to the car with 2 Allen bolts each, through a hinged, black, metal bracket. The important thing is not to whack the bodywork as you remove them from the car!
Curtains?
I use three cheap fleece blankets - what ever you want really. One has the top of its corners tucked between the ceiling and the large plastic cover where the top sliding door bracket 'parks' when the door is closed. The other two are done in a similar fashion down each side, covering the sliding door & rear side windows.
To keep out insects at night a fine net-like curtain (£1.99 in IKEA?) is put across the rear opening.
Having been flooded out while camping in the past sleeping in the car like this is much more reassuring, especially with our weather!
I bought mine almost exactly two years ago - at that time of year it was cheap, I think it was about £170, it's been well used. This one came with an inner tent which can be put inside and fills a third of the tent, to one side - ideal to put a couple of kids in.
Alex.
Spirito di Doblo
(40% A.B.V.)