Thought I'd chime in. I called yesterday morning. The right ff lockoff is broken on my son's '04 Marathon. There really wasn't any conversation or anything. Just a short "That'll be $13, shipping included." I told her I couldn't afford that right now and would have to call back later. Since a few others have had them replaced for free, I will likely try to call again. I posted a similar question in the car seat area last week, and the general consensus was that it never hurts to try, but that with an older DOM like mine, they probably aren't going to replace it free of charge. I LOVE the seat (it was given to me) but I must say, if I had spent some $200+ on it 3 years ago, I would be rather perturbed that this integral part broke, especially since it seems so common. Built-in lockoffs are great, but only if they work! Luckily I have a '99 Civic with switchable belts so I can lock it that way. But occasionally I need to use the seat in a friend's car, and she already has one other seat in there, so I'm at the mercy of which side her seat is on on whether I can use the lock-off or not. And since Britax apparently doesn't allow locking clips, if her daughter's seat is on the 'wrong' side, I'm pretty much, well, up a creek! If they allowed locking clips, that would be different. Because at least then there would be a way to use the seat even it broke. But since they don't, it makes the seat unusable in some situations.
Anyways, sorry I'm longwinded.
Wanted to share my experience. I'm gonna call again. I also just plain hate having anything broken on a car seat.
good luck