Lego Marvel Super Heroes contains all sorts of great cameos. It also includes a Mario Kart joke, made by the Human Torch, right before you go to Thor's home realm of Asgard where they've got a rainbow bridge.
I heard this while playing the PS4 version of the game over the weekend, and I captured it for your amusement.
Good one, Human Torch! Timely, too. How'd he know I was playing the game just after Mario Kart 8 came out???