Was that taken from a running car? I have noticed my truck vibrates a little and I have a very similar effect. I fixed it by shutting off the engine then shooting pic. Could be maybe focus was fooled with ice, I think you have a real good shot here worth duplicating if you are afforded the oppurtunity.
James
How did you know? I was shooting over my shoulder from the driver's seat back through the rear passenger side window. I did not want to get out as to scaare the little critter away. Thanks for the tip. Engine off from now on!!