The Impala… A most loyal companion
God knows how much Dean loves his car. He spent weeks fixing it after his family was run over in it by one of Azazel's cronies back in '06. He nearly had a heart attack when it was stolen by Bela Talbot. When Castiel pulled him out of hell, he smiled at the sight of her (even though, somehow, he had almost forgotten about her).
Dean remembers growing up, spending hours in the Impala listening to the engine growl and the radio blast classic rock music as they drove for miles. He could just look out at the passing landscape, lost in the splendor of his father's '67 Chevy.
Trying to picture Dean in any other car would be impossible.
One night, when he was twenty-one and could legally drink (even though he had drunk plenty of times before then), he left a bar in the middle of Kentucky, hammered. He had hustled some middle-aged men out of their money (which shocked these men, since they were the twice the age of Dean and "far more experienced"). His pocket was stuffed with cash and his brain was addled with alcohol.
He somehow managed to open his car and fall into the driver's seat. He closed the door behind and crawled into the backseat. He found himself laughing at the night he just left behind as he whispered to his car, "You know, baby, I think you and I are going to have one hell of a life together."
The car, of course, doesn't say much. In Dean's mind, she is the best friend in the world. Always listening, never interrupting, always welcoming him with open arms, never judging him. She is the only family he has that doesn't have an opinion on him.
That's the way he likes it.
So he mumbled drunkenly to his car until he passed out in the backseat under the dim light of a streetlamp. In the morning, he will scramble outside as fast as he can so he won't ruin the leather seats. He will lean back onto the hood, letting the hot sun warm his face, because that somehow helps with his hangovers. He will later crawl back into the backseat and enjoy the scents of leather, gasoline, and sweat because he grew up with those scents. Because those are the scents of a hunter.
But mostly because those are his favorite scents and only his baby can provide them for him.
Dean drives the impala with pride. The love of his family lives on through that car—through the rustic scent of leather seats and the edgy sound of classic rock music.
Dean loves that car and with very good reason.