We had a new Goodman furnace installed in a deal with new windows (maybe our first mistake) in the spring of 2006. I wanted to change the filter before we got too far into the winter season. Now I don't consider myself an idiot but I cannot find the darn filter. So even if you consider me an idiot, can someone lead me in the direction to find the filter.

We have a Goodman (sidemounted) GMS80903BNA, if that helps. I

Thank you in advance for your help,
Dan

Possible return air filter grill in the ceiling, take the blower door off the furnace and look up into the ductwork, maybe they messed up and didn't install one.