If the rear air conditioning system for the back seat passenger A/C vents in your 1st generation (2001, 2002, 2003, 2004, 2005 & 2006) Acura MDX has been making a strange sound such as a rattling, vibrating, squealing or screeching noise, you may need to clean the metal filter screen or remove debris from the round “squirrel cage wheel” blower motor fan. Check out my DIY tutorial for the procedure by clicking on the text link or thumbnail image below.
Acura MDX Rear A/C Blower Motor & Filter Screen Cleaning Guide
Owners of the very similar Honda Pilot SUV should also find these DIY maintenance instructions to be helpful.