Sam watched Dean about to get back in the car and leave, and he got scared. Scared that if Dean left, he would end up back inside trapped in the routine that he had been in and that this would become the last time that he would see his brother.

Sam couldn't that this be the last time. No. He wanted more, if only just a few hours.

"Dean... could I maybe catch a ride? Not going anywhere in particular... I just need to get some space and clear my head." His hands clutched the shoulder strap of his bag.

He had all he needed there. Laptop, book, wallet, phone. He could buy clothing elsewhere.

"I mean, if it's not any trouble...?" Sam bit his lip. Maybe the few hours in the Impala would help him really get what he wanted to say out.