[ROCKLOBSTER]

As a dog-owner, I wouldn't do that with my dog but I wouldn't consider it cruel unless it was in the winter time or in inclement weather.

So what about people who let their dogs ride in the back of pickups or stick their head out the car window? What's the diff?

[SamAdams76]

I would say it is more dangerous for a dog to ride loose in the open bed of a pickup, only because it might jump out of the truck and into traffic (if my dog saw a rabbit or deer on the side of the road, she would be gone in a heartbeat). So in that situation probably safer on the roof rack in a cage.

As for hanging their heads out car windows, I let my dog do that all the time but worry that something might get into her eye.