This project is a simple remove and replace that replaces the stock paper air filter with a reusable K&N unit. I have used these units for years in a variety of vehicles and love them! Once you get over the initial expense they are very economical.
"K&N automotive stock replacement air filters are made with an oiled cotton media that is washable and reusable. They are designed to achieve high, virtually unrestricted air flow while maintaining filtration levels critical to ensure long engine life. " K&N website
This HHR air filter housing is very different than your "normal" units. Because in order to change it you have loosen two air hoses and unplug the MAF unit just to get to the point of lifting the housing out! Then you flip the unit over and remove 7 torx scews on the bottom side so you can split the unit and replace the filter. Phew!