Right, so I know this fic is in here somewhere, but I've been trolling trawling (both technically correct, but the alternate meaning for the first makes the sentence a bit suspect) through the tags for ages with no luck so I'm going to do it the easy way.

I'm looking for the Sam/Dean fic where Dean constantly calls Sam by pet names and Sam keeps thinking he's talking about the Impala. One example is this hot lady in a restaurant with a really nice car asks Dean if he wants to go for a 'ride' and he says something like 'there's no one for me but my baby' and Sam totally misses the point. Eventually, they get on the same page and there is schmoop.

Thanks very much all!

EDIT: Found! It's And One More For the Road by vicious_trade. Y'all are awesome!