Natasha is vaguely suspicious that one of the reasons Clint said yes to his own quarters at Avengers Tower is because he got a good, long look at Tony’s garage. While Bruce and Tony are best friends in the lab (frequently joined by Jane, who has slowly been drawn into the weird little superhero family they’re building), Bruce barely knows which end of a wrench to hold. Clint, on the other hand, has loved classic muscle cars for most of his life, and Tony is more than happy to indulge a fellow addict. Natasha once spent an almost unendurable two days in London stuck in a two bedroom apartment, listening to Clint describe, in all-too-loving detail, a rebuild on a 1972 Satellite, the first car he fell in love with. Clint retells the story to Tony, and it becomes a bonding moment. Go figure. They disagree only in one detail - Clint scorns anything not American-made, which means a whole wing of Italian and German engineering is ruled out, and Tony gets to call him an unsophisticated lout. There's still plenty in the garage for him to play with.

The rest of it here at AO3! (http://archiveofourown.org/works/464795)