I'd say you're more likely to pick up a stone chip on am rural A or B road than a motorway 
mmmmm my only stone chip is from motorway.....cars travelling at speed in front flick em up......
95% of my driving is done on country roads.....never got one there........yet.....
My biggest annoyance on country roads is bugs.....bra would be good to keep them from car front. But i would have to have a paper bag for my head too
