Mine slid in L as well... the first time it happened, I thought to quickly slap the shifter into D. As for the seat belt, it’s a safety thing... it lets you know the car is not in Park when you unfasten the belt to get out. My mom was complaining about her Model S going into park when the dogs were jumping around the car... turns out she had just checked the mail and was driving to the house w/o seat belt on and the car goes into park if you shift in the seat w/o seat belt. Very bad for the car when in a car wash with a conveyor belt. The bolt’s “reminder” won’t screw you up in a car wash.