Unless he climbed into a van that had a blanket in it (some people do keep one in the car)....The blanket throws me a bit....IMHO
I have 4 blankets in my minivan. Even though there is rear heat it's still cold in the third row if I'm hauling more than my 2 boys (this is pretty often). Also to save the seats when sweaty, wet or muddy teen boys after games. And wet or muddy dogs to lay on.