[BigTallV]

A shot of lysol into the cowl area while you have the fan running on high in the passenger compartment will help. So long as the system pulls in a percentage of fresh air from outside, the lysol will get sucked in as well and make its way over the ductwork and core/coils. I get this only at certain points in the year, even at that, not regularly. Most noticeable is the first time turning the A/C on in the spring or summer.

 

[BigTallV]

Auto grade stuff will work too. I just thought Lysol as it's common household available stuff. Quick and easy, any scent disappears within minutes of use.

Just find the air intake vent and give it a shot with the fan on high. May not give the most even distribution, but something is better than nothing.

I wouldn't use bleach as you have no means of neutralizing it.