If the car was "constantly beeping", you were either not wearing your seat belt (unlikely), speeding with speed limit warnings turned on (though there are plenty of mapped areas that have outdated speed limits and no updated signs on the road to replace them), or approaching stopped cars way too quickly, triggering forward collision warnings.
I'd say it's pretty crappy ui if a new user can't immediately identify what's causing the beeping. If I'm in car going highway speeds and it starts yelling at me not knowing what to do will result in a more dangerous situation.
