Have not been stopped on back roads. Have crossed the border on foot a hundred times, and inside-the-border-checkpoints in vehicles another hundred. Once in a while I'll have them peer in the windows, only one ever asked to look in the RV which could have carried a dozen people.
But usually I get the wave through, or a quick hello to see if I have an accent. I often feel like June Cleaver, sailing through above reproach, because of light skin and blue eyes. It is a very bizarre system and a colossal waste of money, since people and commerce have been crossing the border for hundreds of years. Imagine your people living in an area for a dozen generations, and you still get stopped for driving while brown.
Our part of the border has occasional violence and drama, but usually is very low key. So far I think the ICE goon squads concentrate their efforts where population is dense.