Booster question - big 7 year old

[abstonka]

Need a booster (not backless) for DD (age 7, 64 pounds, 53" tall) for my car, and my research is way out of date. We are finally ditching the Apex in DH's car and will move the Nautilus to his car. DD has a hard time reaching the door handle in my car in the Nautilus, which is why the new seat needs to go in my car.

My car is a 2003 Ford Explorer. We have two Radian 65s and the Nautilus in the back seat now. It's a tight squeeze, so width is a factor.

DD does not complain about still being harnessed, but I think she is mature enough for a regular belted booster. The only concern I have is that she'll accidentally unbuckle the middle seat's buckle. I cannot use latch for it.

Ideas? Suggestions? I would prefer to stay around $100 on this.

[Joolsplus2]

The Safety 1st Air Protect booster is the best I've found for tight squeezes...it's tall and comfy but has a very narrow rear end between the seatbelt anchors and the armrests flip up for easier buckling. Britax Parkway might also be a good choice, though I've heard some mixed reviews on it fitting next to other seats. Stick the rough side of sticky velcro on the middle seatbelt button, that'll be at least a tactile reminder not to unbuckle that one (if it happens repeatedly, you may just be able to turn the seatbelt around so the button is impossible to accidentally touch).