I have family on both sides of the border. I've been across the border somewhere between fifty and a hundred times myself, and my dad, who I must say is kind of a confrontational person, has been across at many hundreds of times. I've never heard of anyone being asked for an inspection of their vehicle.
We just say no when asked if we have any fruit or vegetables. Even if we have a large box of fruit plainly visible :-). As far as I'm concerned, it's security theater, just like the airport checkpoints and the wall. I think all they really care about is what the semis are hauling.
Do you have any experience with quince? They are a wonderfully, powerfully, fragrant fruit that grows in cold climates. When I went through last fall, I had a box of quince and a box of apples. My entire van smelled like essence of fruit. No hassles.