I've beat up several Garmin GPSs over the last 10 years. Typically, it's the screen that goes. It gets so full of scratches that it is hard to see. One day, I was digging through my desk drawer and ran across an old pack of screen protectors for my PDA. It occurred to me that what will protect a PDA will protect a GPS.
I took one out and cut it down to size as shown in the picture below. Turns out the Garmin CPS60 screen exactly fits some of the lines. As you can see, cut the protector following the guides for the Palm Z22 except go one notch up on the top.
Be careful when you put it on to work from top to bottom squeezing out the air bubbles as you go.
I've had this on my Garmin for my last several trips - some of which involved the typical climbing and banging around - no scratches.
Garmin does produce a case of this model of GPS that includes screen protection. It's probably just as good and, if I did not already have these other protectors, I would go with it. The only drawback is that the case covers the access ports in the back for the car battery connector and the USB. So you would have to remove the unit from the case to use those features. In addition, I was told that it will not fit into the car clip-on holder inside the case.