It's not height actually that cramps your style in a 3-series as much as girth. If you'd ease off on that biscuits and gravy and those fried-cheeseburgers-on-a-stick, you'd probably fit a 3 well.
Anyway,
aside, this new 5 is looking pretty good. My fingers are crossed that they didn't overload it up with fun-sapping modernity.