+1You might want to browse/search through the Mobile Electronics section. Many Element owners have installed aftermarket nav systems (as well as beefed up the stereo). If you are considering doing it yourself be sure to read the "stickies" at the top of the page. Several member have jumped though hoops to document information for us.
I am very happy with my Kenwood DNX8120 btw. I would do some research for good installers in your area.