I had a 2012 SG (not SGL, I understand they are slightly different) that did not work with my third row outboard seat belts. At all. The shoulder belt would not retract. The 2013 SGL did work for us. The shape of the seat is completely different, so perhaps where the guide sits in relation to the seat belt is different on the 2012 vs 2013 even though they have the same guides? I am just speculating because I no longer have the 2012. I know some people have better luck than others with certain seats (e.g Turbo w/safety surround - some people here have used it with success but at the height my DS needed it the shoulder belt wouldn't retract) so YMMV but we used the SGL for a month or two and the shoulder belt never had a problem retracting. Also, the lap fit was fine on both the 2012 and the 2013.
This is very helpful. Thank you so much! I think it was the position of the belt guide, not the guide itself, so maybe I should try the 2013 in my car when I get a chance. The 2012 model is fine, but it's so annoying to have a booster that I can't use in my car, the car she rides in 90+% of the time.
If your head rests are removable or adjustable (mine are neither) you would probably get an even better fit. You may want to double check that Britax doesn't require head support.
They don't. In fact, they instruct to remove the vehicle head rest if it will improve the fit.
I'm all the sudden worried someone will buy this seat, have it not work, and get mad at me! If you can, try before you buy. That's my disclaimer
I can't imagine someone would. You're going out of your way to be helpful, something I appreciate and I'm sure others do too. No one can guarantee someone it will work for them unless they actually try it.
My DS is 6.5 and 45" and 42# and doesn't fit our Monterey because the shoulder strap is to close to the edge of his shoulder. He is on the verge of outgrowing his radian xt. I am trying to decide between the parkway sgl, recaro performance booster, kiddy cruiserfix, or a new nautilus and keep him harnessed for another year+. Pictures of the performance booster in use would help, especially with a slim child.
If the Monterey belt fit is too wide, you may want to look at a Turbo. They fit slim kids well. I tried several boosters with my slim, but tall, DD. I don't know about the 2013, but the 2012 Monterey was a narrower fit on her than the 2012 SGL. HTH.