1. Dean still has his red-plaid-shirt-of-angst - most famously worn in AHBL2 during his soliloquy over Sam's dead body...but also worn during Shadow, when Dean tells Sam that he wants them to be a family again. I guess Sam must have kept some of Dean's clothes after he died - and put them in a storage unit or something (Dean had to wear Sam's clothes in Lazarus Rising, so we know Sam didn't have them in the car.) It's either that or Dean bought himself a new red-plaid-shirt-of-angst. In anycase, in Sympathy for the Devil, Dean pushes the shirt out of the way when he rummages through his bag to find the Castle Storage card.
2. In Sam's contact list on his phone, which he scrolls through in Free to Be You and Me, "Dan" has a Vancouver area code. My other question of course, is "who are these people? Sam and Dean don't have any friends!" :-P Also, slightly odd, is that Dean's cellphone has a New York area code...an area code right in the heart of New York City.
Completely random useless facts, but facts nonetheless. I should have looked to see if Sam had Castiel programmed into his phone...haha, that'd be kind of funny. 1-900-Angel. :-P