So far I think I've determined there's 156 buildings, and 103 cars... at least, that's the consistent highest number I can get for those stats. Some buildings are cheekily hidden under others... the cars though, I swear a few sneak in after you smush the majority of them... I might be wrong though.
Viewing post in Step 'N Smush [Macro Playtest] comments
Yeah I think what I'm seeing is the hitbox (for want of a better term) is a tiny bit inconsistent at times. Sometimes the car gets smushed, sometimes it doesn't (when it's on the edge of a stomp/special attack). The kick strike seems to be the most problematic in that regard... The 103 number comes from testing what states are considered "cars crushed" and then trying to get all of them... game is still fun though!