Avengers: Age Of Ultron - 32 Easter Eggs, In-Jokes And References

For a good portion of the film, Tony Stark rocks a famous Bow And Arrow T-shirt featuring Bruce Lee as a DJ spinning discs. 

A nice pop culture reference in itself, but it has another level to it as oddly, the t-shirt seems to be Robert Downey Jr's own. He's been captured on film wearing two versions of the same design away from set.