I read all the posts here regarding the rear facing child seats and I know that these seats are for kids at least 37" tall and up to 77lbs but can someone who has children sitting in these seats tell me how much headroom there is for the kids? How tall are your kids? I'm a little concerned with them hitting their heads on the back window if an accident happens and also if it is at all claustrophobic back there. I'm currently on the fence between getting a Model S or putting in a reservation for the Model X as I will have my wife and three kids under 5 to consider. My 4 year old would now be big enough to sit in the rear facing car seats but if it's not going to be comfortable for her, it won't make sense for me to get an S. And putting three in the backseat of a sedan will be a hassle, especially the middle seat! I do know of the heat issues and sunlight issues but I haven't read much on headroom for the kids in the rear. If anyone has experiences here, can you chime in and share? Thanks!