There was a kind of naive white kid and a streetwise black kid, both like 10-11 years old. The black kid is kind of a junior thug and takes the white kid on a bunch of urban misadventures. What I remember most is a car chase where the white kid is forced to drive and he keeps screaming, "I don't know how to drive!" (The black kid does and had been driving before then.) I think the black kid had a trenchcoat and sunglasses most of the time.
I happened to think of this movie yesterday and have been dying to find out what it was.
I'm thinking 80s, as I'm pretty sure I wasn't more than 10 years old when I saw it.
I'm pretty sure you're thinking of the movie Big Shots (http://en.wikipedia.org/wiki/Big_Shots_%28film%29) (1987).
Yes! Thank you!