My Audi and Mercedes Hold Mode had collision sensors to tighten the seatbelt, adjust the headrests, and apply the brake forcefully in anticipation of a rear end collision so the car would not be pushed into the cars in front after the impact, and to further protect the passengers. It seems Hold Mode on the Tesla just tries to use regen forces to hold the car in place with no real guarantees, and the manual says it may not even work well on steep inclines. I am wondering why the car doesn't figure out when to apply brakes to maintain the held position until the driver decides to release it, or perhaps in the event of a pending rear collision. Am I correct in assuming not to rely on Hold except as a convenience and to apply the brakes (and pray) if I see a car approaching too quickly from the rear -- that the car will lurch forward in Hold mode and the brakes will not be automatically applied?