Mike,
I can't vouch for whether or not it'll not slide around, but one way to get around any seat belt positioning issue is with the new Britax Super Elite:
http://www.childseat.com/resultsdetail_seats.cfm?pro_id=26
It's one of a new breed of carseat where it keeps a child in a five-point harness until they're about 8 years old (up to 80 lbs or 53" in height, as generalized measures). On paper, safer than a belt-positioning booster because it relies on the five-point harness.
Downsides? The seat is expensive like all Britaxes -- about $200 and its availability has been very limited because of production issues (sound familiar?). Also, if your daughter feels she's outgrown a five-point harness she may resist using the seat.
I plan to put my son in it once he outgrows his Britax Roundabout. He should be accustomed to five-point harnesses so the transition should not be an issue.
A nice user-contributed database of car seat compatibility can be found at:
www.carseatdata.org
Unfortunately, while there are database entries for some infant and convertible seats in the MDX, there are currently none for booster seats.
I can't vouch for whether or not it'll not slide around, but one way to get around any seat belt positioning issue is with the new Britax Super Elite:
http://www.childseat.com/resultsdetail_seats.cfm?pro_id=26
It's one of a new breed of carseat where it keeps a child in a five-point harness until they're about 8 years old (up to 80 lbs or 53" in height, as generalized measures). On paper, safer than a belt-positioning booster because it relies on the five-point harness.
Downsides? The seat is expensive like all Britaxes -- about $200 and its availability has been very limited because of production issues (sound familiar?). Also, if your daughter feels she's outgrown a five-point harness she may resist using the seat.
I plan to put my son in it once he outgrows his Britax Roundabout. He should be accustomed to five-point harnesses so the transition should not be an issue.
A nice user-contributed database of car seat compatibility can be found at:
www.carseatdata.org
Unfortunately, while there are database entries for some infant and convertible seats in the MDX, there are currently none for booster seats.