protection

I use a 1/8" mesh welded wire screen cut to fit in front of the A/C condenser. I had a cracked A/C condenser from a rock hit. The guy at the A/C shop said he was very busy when the nearby freeway was being resurfaced with a layer of asphalt. Driving in light traffic is low risk, it's the cars in front of you throwing rocks in the air that cause problems. Like getting on a freeway behind a large truck that is throwing off rocks from the tread that it picked up on surface streets. I've seen several times rocks bounce 6ft in the air from trucks.
Sort of related - I think every time I have had a nail puncture a tire it's the rear tire after the front one bounced the nail. Running over a nail laying on the road is not going to puncture a tire, but when it bounces up and gets under the next tire...