Now that I have an idea of what most things are on my Tesla Model S (I've had it 8 days and done a few test drives before too so I'm not completely clueless), I think it is the best time to read the manual, so that it all sticks, and I'm not overloaded with stuff I don't already know. Probably the first day I got it would have been better, but I've been working a lot, so that wasn't possible. I'm on page 18, and it says "Seat Covers Do not use seat covers on Model S. Doing so could restrict deployment of the side air bags if an accident occurs. It can also reduce the accuracy of the occupant detection system, if equipped." I don't like having my head pushed forward by the head rest, since it is extremely uncomfortable, debilitating, painful, and changes my posture. In addition, I have a wide trunk (as well as a long trunk), so I like not having the side jabbers (as I call them) on the seat, since they would give me sores and muscle cramps quickly, as well. So, to alleviate that in the many cars that have one of those problems, I add a cushion to the upright part of the seat. It's a few inches thick. It doesn't go up to the headrest, and has no bottom, even though those are options. It works very well for me. I am comfortable and don't have the above problems. Now, the problem: I want the safety of the Tesla, so I don't want anything impeding the air bags. So, I don't know what they mean by seat covers impeding side air bags. How would a cover on a seat impede a side air bag? Could my cushion impede the side air bags? Does anybody have an idea of how the covers would impedede the bags, and how a cushion would impede the bags? There is an airbag diagram on page 31, and item 3 shows side air bags that may or may not be inside the seats.