If you're a car guy, as I am, you can appreciate the engineering and design that goes in to every car you see. I love being able to sport my favorite car or car company on my desktop but have had trouble finding pictures worthy of desktop quality.
I then discovered http://www.autowp.ru/ (It's in Russian but if you have Google Chrome it will translate for you no problem)
This site has a myriad of wallpapers and high quality pictures from almost all of the car companies in existence.
Check it out.
How to wash the correct way (no scratches, perfect shine and smoothness) guide coming this weekend if I find the time.