The video above is an east to do tutorial on how to repair, install, fix, change or replace a dirty, dusty or clogged air filter on a Cadillac CTS. This DIY video is applicable to the Cadillac CTS, years 2003, 2004, 2005, 2006, 2007, 2008, 2009, or 2010.
You can get a replacement air filter for your Cadillac CTS over on Amazon for around $12 plus shipping and handling unless you have Amazon Prime then it should have Free Shipping.