Where to put freon inside a 2002 Chevy Impala?

You don't put freon (refrigerant) directly *inside* a car. The refrigerant goes into the air conditioning system's refrigerant lines which are part of the AC system, not the car's interior. Adding refrigerant requires specialized equipment and knowledge. Do not attempt to add refrigerant yourself.

Improperly adding refrigerant can damage the AC compressor and other components, leading to costly repairs. Take your 2002 Chevy Impala to a qualified mechanic or AC specialist for refrigerant recharge. They have the necessary equipment and expertise to safely and correctly add refrigerant to your car's AC system.