I have the Britax Marathon Classic (bought in February of last year) and I'm wondering if anyone else who has this seat feels like they can't get the straps tight enough when rear facing? When I pull the strap to tighten, it's like it hits a certain point with a light clunk and the strap will go no tighter. I can pinch a bit at his shoulder and, although it isn't what I'd call loose, it isn't the tight, almost non-pinchable strap that it should be.
I called Britax and they ensured me that this was "normal" and that with this particular model, it's okay to have a little more slack. This sounded like a total line to me as it goes against everything I've ever read. I did a few internet searches looking to see if others have had this problem with the Marathon Classic and I see very mixed answers that they got from customer support. Some said that once it hits the "clunk" point, you have to do short pulls like a ratchet (this did nothing for me), another suggested pulling the shoulder straps taut from the back and then pulling the tightening strap (again, no difference). I have never seen the "a little slack is okay with this model" line. I should also mention: the seat is absolutely installed correctly, the straps are in the correct shoulder positions, my son is plenty big for it and it's not that I'm just weak and can't pull it.
I have to admit, it makes me nervous that I feel like I can't get the straps tight enough and I'm pretty much ready to give up on this seat and get another one just for piece of mind. Before I did that though, I thought I'd get some other opinions/experiences. Maybe I'm missing something or there's a trick someone can share? Help me, car seat gurus!