Short deadpan voice lines like this became popular on soundboards and in edited videos because they work without any context. The phrase states something completely obvious about being inside a car, so editors can drop it into travel clips, roleplay scenes, streams and reaction edits where the joke is pointing out what everyone can already see. Its very short length makes it easy to loop, layer over footage or use as a quick reply, and it has stayed in rotation as a simple, flexible car reaction sound.