I have an 06 Vue that I have installed aftermarket radio's into, it should be the same idea. When you remove the factory radio, you loose chimes and onstar, so no door ajar warning, no seatbelt warning chime nothing. If you want everything to work you need to find a harness that hooks to the Outlook and works between the stereo and the Outlook. Mine was $100 or so about 4 yrs ago. You will need to decide how important your chimes are to you, then you need to check out online or at a local car stereo installer to see what is available for the 07 Outlook. Some people won't even recommend swapping the factory radio. I wouldn't recommend cutting the factory harness, that would be really messy and probably cause you some huge headaches. Good luck.