First off I do plan on getting the seat inspected. I have looked at youtube videos on installing this seat rear facing. It seems as though all of them show that the seat does not move more than an inch side to side but movement front to back is "normal" and allows the seat to rebound, if this is the case then why do they show installs using the tether as well? Anyone have any experience with this?
Re: installing britax advocate rear facing
I am a tech, so I will try and answer all these questions.
First, there are currently 3 brands on the market that allow for the rear facing tether. Those are Britax, Combi and Diono (previously Sunshine Kids). The tether acts as an anti rebound mechanism. So, while it is not required it is definitely recommended.
The prior poster was talking about the Australian way of tethering, which brings it above the seat and attaches to the tether anchor in the back. You want to use the Swedish method, which uses the D-ring that comes with the Britax seat, to make a tether point on the floor of your car. It is important that you use a non moving piece. I will link you an article that might help explain.
When you switch to forward facing, the tether should ALWAYS be used if your vehicle is equipped with a tether anchor. I believe all cars newer than 2000 (?) have them. The forward facing tether helps reduce head excursion in an accident.
If you need any other help, you can visit the facebook page Car Seats for the Littles. I am a tech on that page.
https://carseatblog.com/12749/how-to-use-a-rear-facing-tether/
I switch browsers on my mac, so I am not sure how to make it clicky now. Sorry!
Also, they show the tether in the video because if you can use it, then they want you to do so. Movement at the top of the seat is normal for all seats on the market, these particular seats have been tested with the tether, which is why they recommend it. There still will be movement at the top with the tether, but it is not going to be as much front/back movement as seats without the tether.
If you install it with the tether, just make sure you are only taking out the slack in the tether, and not pulling it super tight making the seat recline more.
Thank you so much for the explanation! DH went ahead and installed it using the tether with Sweedish method (so the tether is hooked to the seat rails behind the passenger seat on the floor).