Firstly, if it Rained Cars, some people may keep on waiting patiently for a superexpensive Car to drop from the sky!
Secondly, if it Rained Cars, cab drivers will not be happy about this situation!
Thirdly, if it Rained Cars, everybody will now own a Car, but there will be no road left to drive a Car!
Lastly, if it Rained Cars, even our pets may now start driving Cars!