I try and keep it straight up unless Im driving an old-school whip with no air bags.
'Gangsta Leanin' (for me at least) is reserved only for the kinda cars that were built for you to drive in that position. Example: Luxury sedans built before 1991
Cats all over where I live be trying to lean like retards laying in their car, and I think its stupid mainly for 3 reasons:
1) you look like a damn idiot with your head in the back window driving a hoopty
2) Cops love to pull over people who drive like you
and finally...
3) IF you hit something and your airbag deploys, the odds of you breaking your nose, face, breaking your arms, getting a concussion, suffering brain damage, breaking your neck, getting whiplash etc are increased by ten. The airbag is supposed to deploy into your chest, not your crooked ass hat wearing head.
honorable mention: it's much easier to weave traffic if you're sitting straight up and in the proper position. It makes you more aware.