I wouldn't bother reporting to the council. I witnessed a car throwing all its takeaway packaging out of the window and was similarly outraged. I took the car number, description, time & place and reported it on the Council online littering service.
To be fair to them, they did call me back the next day but only to tell me that they don't prosecute or follow up car littering anymore. So no deterrent whatsoever for those that choose to do this.
I really can't understand why anyone thinks it is acceptable to just throw rubbish out of car instead of taking it home and disposing it in a bin properly.