Car window mounts are great for wildlife shots I believe, as much wildlife is more approachable in a vehicle than on foot.

A Scrooge like me would use a piece of small size pipe insulation, the foam type that slots over a 15mm pipe, cut it to the length of the car window and then just slot it over the top of the open window when needed , job done, and still enough money left over to buy the other half some flowers and keep in her good books when you have been out all day taking photographs  

 

 

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html