A/C circulation

Just found something interesting and thought I'd post for others.
My A/C was a little stingy with regard to airflow last year. I finally dug into the smugglers trunk and looked around. What I found was that over the years (it's an 87), the moisture and dust had blocked roughly 1/2 the evap unit. I plugged the air returns in the footwell with rags, shoved a shop vac hose under the evap, sprayed 409 liberally, and blasted downward with a hose nozzle. It cleared about 90% of the blockage. no water in the car at all..

AC is 3x as strong now and doesn't smell like a frog farm..

Where is the evaporator located? I have a 1988...