Many years of abuse
Many thousand miles
Many, many rocks from cars in front of me before I passed them
Been on it's roof more than once
I have a screen that sits about 1/2" off the front of the radiator and only one rock ever got all the way to it - big sucker that left a dent in both the screen and the rad, but never have I had any issues with a leak or safety.
Originally it was low and down behind the seats and we had all sorts of overheating issues. Up in the air where it gets flow is the way.