Thanks for all the advice.
Actually, it's my mom's car and it has an odour problem. Tried the
Heater hot air thing, dettol/Lysol also no difference.
Wanted to use a steam cleaner and install a 3M carbon filter but
could not find the hole to shoot the steam nozzle. I did read about
the air filter from the forums, but thot all along is an optional
accessory. After checking the manuals as mentioned by previous
poster, discovered the secret compartment behind the glove
compartment. Even with the filter removed, the odour problem
persists. I think it's the evaporator coil that's giving off the
odour. But since the fan rotor is between filter and the coil, need
to find another way to get to the evaporator coil.
Once agian, thanks for all your help!