In the several years of owning a '98 Isuzu Rodeo, I never got a crack in the windshield and I drove the same roads as I did in the 4R. I've already had to repair 3 cracks in the windshield--and I've only had it since December 17th!
The only advice I can give ya is to carry some clear vinyl tape with you (my insurance agent gave me a sheet of these when I got my coverage), and as soon as you get a chip or bullseye, pull over, put a sticker on it, and in the next several hours, get a glass chip repair place to fix it.
The tape keeps water and other crap from getting inside the chip, and it "supposedly" keeps it from spreading instantly. All three chips I had, I did this and after the repair the chips never expanded. I can barely see 2 of them, and the worst one (the bullseye, about the size of a dime), I can see the round area slightly in the right light.
I dunno about why the 4r is so prone to chips and stuff, but there's something about either the body design and how air flows over the body, or the angle of the glass. I still love my 4r, but I know of 2 other 4r's that have the same issue with rocks!:moping: