Those avatars look great!
If you use "free transform" in PS and squish the pic in from the sides, will that work? How did you add the shadow?
Can't give you all my secrets, but just a simple "transform" isn't enough. that would also squish the tires etc which makes it look wierd.
I thought I'd add one more. I had a decent photo of Dave Connor's Expedition Americas Cruiser so I did one for him too.
oh...and even though it's not a cruiser, I did one of my old pickup, "Aqua-Velva". It was more of a rockcrawler, but I still loved it.