Came across this interesting accessory which may be an aid for those who, like me, occasionally find the best way to sneak up on birds is in the car.

http://www.ebay.com.au/itm/182118462...%3AMEBIDX%3AIT

It was ostensibly designed for shooters, the rifle variety, as an aid to steady their firearms.

I can see it being quite useful to prop up your gear, particularly when using a big lens.