I have talked to my salesman at the dealers about a new Prius and am going to get put on the list (3 months). I have question on the cabin air filter. Where is it located, and how do I change it? If it is someting I can do why have the dealer do it. Everything I have read on this site has been very helpful. Andy
It is behind the lower glove box, it is very easy to change yourself and you can save a bit of money by ordering the replacement filter online or by making your own filter by cutting up a cheap air filter from Wal-mart or Home-Depot and taping the edges. I believe there are instructions in your owners manual. Also, John1701a.com's user guide has instructions and nice photos on page 27: http://john1701a.com/prius/documents/Prius_User-Guide.pdf
If you're using filter media that might "unravel", then tape edges. Otherwise no, it would only decrease the surface area for air flow.