I installed a factory navigation in my 2008 silverado but don't have the gps antenna or vss wiring. Anyone have those items for sale or know the oem part numbers? Everything works as it should except I have no clock showing on the radio. I messed around in the settings for the clock adjustment but it show no numbers? The screen has a big enough scratch in it that bothers me. Anyone recommend a place to have the screen replaced, preferably without a super long turnaround time? Or is it simple enough to purchase a new screen and do it myself?