I put in duct work with a door, pneumatically controlled. It gets the air from the passenger side where the mail box vent was. The fan moved to the added duct work. On hot humid days I close it, all other times it's open.
I adapted the factory underdash vent box to the Classic Auto Air system and have thought about getting the passenger side fresh air vent working again.
The fan motor does stick out toward the right quite a bit though.
