Never hit one ,but drove past a bunch that were eating roadkill .when the flock got up one managed to take a dump allover the windshield and roof of the car ,had to stop at the first place I could and hose it off then to the car wash for a major cleaning ,stinkyest plie ever ,still can make me want to gag just thinking about it.
They puke out what they've eaten to take off faster. Had a big, bloody wad of puke hit the windshield when I barely missed a buzzard once. Like you said, it was a tad stinky.
Only time I actually hit a buzzard, it glanced off the windshield, but not before knocking an egg out, that splattered all over the glass and roof. That required a quick car wash too.