Now that I have looked up the definition of plenum (I will be using that in sentences at the bar tonight), I thank you for the response.

So, since I occasionally still get red dirt flying out of the vents, my plenum needs cleaning? Are there any parts I can/should remove in this process, or just start drowning the wiper area in a mild bleach solution?

Any other cabin ventilation cleaning tips for the VX?

Bim