Our new Model S is set to arrive in a couple weeks. Our daughter is ready to move out of her forward facing convertible car seat into a booster but we have been holding off until we got the Tesla because we want to be sure the new seat fits properly before we start using it. Our son is also ready to move out of an infant seat, so the timing is working out pretty well. We are looking for something that has a 5 point harness and later converts into a booster where the child is able to buckle themselves in. I've read several threads and it seems like everyone is saying a seatbelt extender is necessary. The Model S has now logged a lot more miles since previous booster seat threads. Is there anyone out there who has found a five point harness to booster convertible booster seat that does not need a seat belt extender? If no, what kind of booster seat are you using for your toddler? Pictures are welcome! Thanks everyone!