I just installed my F90bt in my 2007 hhr from the research I did my car does not have VSS wire unless you use the metra box to keep the door chimes, which to me did not matter for a 80 buck box. It seems to work ok so far have only tested it around town a few times, I am going on a trip next week will see how it goes then. if any one knows if the 2007 hhr with auto tran has a vss please let me know.
thanks