I don't have a picture, because she is FF now.
I know for a fact that I had the belt through the right belt path, its pretty self explanatory, and not only that but I have been installing Carseats for awhile (she's my 4th) I am not saying that I am an expert.. not even close.. I just know the basics.
I'm sure no one meant to seem insulting; it's a very common mistake and an easy one to make, and best to rule it out before looking at other possibilities, yk?
Because our middle row is so far behind the drivers seat, the carseat didn't reach the back of the drivers seat so it wasn't able to help wedge the seat in place.
Wedging the carseat in place by bracing it against a front seat won't correct this problem, though, so it doesn't really matter that you can't do it. It's acceptable in most cases to do this, but if the carseat is coming loose, bracing it will only make you
think you've fixed the problem, it won't actually fix it.
It's really hard to say without seeing the problem, but I would suggest that you install the carseat rear-facing again, but don't focus so much on getting it completely reclined at the 45 degree angle. It's okay for older children to be a bit more upright. That alone may fix the problem. (And then take pictures to show us, that will help, too!
)
Another thought - does the vehicle seat recline at all, and was it reclined when you were having this problem before?
Also, how many rolled towels were you using, and where were they placed?
I'm a bit hesitant to suggest this, because I would hate for there to be another issue that you've missed, so definitely rule out every possible problem before coming to this conclusion! But... the fact that it was coming loose in that way may even be normal. Again, it's impossible to say for sure without seeing it, but it's normal and acceptable for there to be movement at the top of the shell on a rear-facing carseat. I could completely mess up the tightness of just about any rear-facing carseat just by grabbing the top of the shell and forcing it down or pushing it forcibly - that doesn't mean the initial installation was poor.
In a wreck, the top of the carseat is going to rotate downward quite a bit, and as long as the seat was correctly installed in the first place, that will be OKAY. But because that movement is normal in a wreck, it's possible to loosen the install over time, especially if it was getting leaned on.