I have a 1999 Boxster with the vent debris problem. I currently have the dash off for an unrelated issue, and decided to look into the debris problem at the same time. I'm trying to decide if I go down the full disassembly route or not, and have a couple of questions about the two different options. As I understand it, the options are:
1) Easy option - single flap repair. Access the hot/cold mixer flap from the front trunk. Flap is removed by using dremel tool to cut away flap upper bushing housing. Flap is removed through hole where heater core is mounted. Re-foam single flap. Reassemble.
2) Difficult option - dual flap repair. Remove heater core from front trunk, remove dash and dash mounting structure, evacuate A/C system, remove entire HVAC assembly from passenger compartment, disassemble HVAC housing. Re-foam both flaps. Reassemble.
Is this an accurate summary of the two options? If so, what does the second flap do? Is it for switching air between footwell/dash/defrost? Or outside air/recirculated air?
I'm thinking it's a better use of my time to skip the full repair option, to not further disassemble the dash, skip evacuating/refilling the A/C, and just re-foam the one flap from the front trunk. But I want to make sure I'm not missing some obvious justification for doing the full disassembly.
FYI, here's a picture of the flaps, taken through the passenger compartment center vent location.
Thanks in advance!