As a Tesla owner I always keep a hand loosely on the wheel and I never get a warning. In fact the only time I've seen the warning was when I deliberately kept my hands off to get a feel for when the warning occurs and what it looks and sounds like. I still haven't been brave enough to let the car trigger the fail safe "come to a stop" scenario when ignoring multiple warnings, I also wonder if doing so might cause a black mark against my Tesla account ;)