They were seen speeding down Interstate 8 on the way to Tucson, Arizona.
Well, maybe it was us speeding down the highway on our way to Grandma's house.
You gotta be fast with the camera though. Find an interesting cactus up ahead, in this case a Sagauro, slow the shutter speed of your camera way down, and pan with the cactus as you go by. It works best if you have someone else drive. And take lots of shots as most will come out as blurry blobs.