When Dean says "...and Mr. Comatose over there." Castiel's coat is covering his right side, but in every other camera angle his coat is fully to his sides on the bed.
As Sam says "No, but you can distract them." Anna's bottom lip goes from clean to bloody in the next shot without her being touched in between.
When the boys first pull up in front of their parents' house back in 1978, the address is 485 on the house. Directly across the street, the house has an address of 2016. That is way off, it wouldn't be like that.
The wheels on the Chevelle that Sam & Dean drive when they go back in time would not have been available in 1978.
When Anna goes back in time to land on the Trans Am with the Firebird wings on the hood, she is in 1978. Zooming out reveals the Trans Am is a 1981 model.
When Michael and Dean are talking, some of Dean's audio is cut, but his mouth still moves.