In reply to Pete Dangerous:
Multiple options, all with varying degrees of effort required:
1) Get in your sleeping bag the "wrong" way up and put the hood over your face. Pros: super easy. Cons: hood in your face.
2) Leave the parcel shelf pulled over, and stick your head under it. Pros: easy-ish. Cons: need to slither round to sit up, looks a bit wierd, have to orientate yourself the "wrong" way round in the car, feels claustrophobic.
3) Cut out some old roll-mat (foam type of course) to match your windows. It can then be pushed in/out at will, without needing any permenant fixtures. Pros: no permenant fixtures, cheap. Cons: need old roll mat, some time and effort (both to make and set up).
4) Fit some curtains. Pros: clearly the best, thats why you use them at home. Cons: takes a while to make, really obvious to all and sundry that you kip in your car, can get in the way of visibility at junctions even when pulled back, look really shit.
Personally I opt for 1, and used to do 2 when I had a Landrover with a high parcel shelf. Have been thinking about 3 but have more pressing jobs to do.
Post edited at 15:19