depends, if you just wanted to use the controller chip and knew the layout of the matrix yea, if your just going to wire tap the matrix then you have a whole stripped out busted keyboard to deal with over 3-5 buttons

but a 3$ chip, a hand full of electronic parts and less than a page of C sounds much easier to me than probing out a 20000000key matrix or shoving a keyboard under my dash (course I already have these items and experience with them, but I dont mind helping if you were to go that route)