When I did the Pelican wallpaper page I never considered widescreen images. I guess times, and monitors are changing. I am low on space on my site right now so I don't think I'll be adding more sizes in the near future.
Here is another wallpaper site in australia. There are some porsches mixed in with other cars. The largest resolution is 1024x768 though so they are a bit small:
http://www.wallpaper.net.au/wallpaper_automotive1.php
Here's some in Germany:
http://www.wallpaper-area.de/wa-2-3.php
http://www.wrc-wallpaper.de/Porsche.html
Go to
images.google.com and search for "porsche wallpaper", and you will find more.