The harness is light blue and is an EZ harness 103Z/S.S
Foremost, at least you know which vest he is using on the bus
. The instruction manual for the model can be viewed on the E-Z-On website
here. It might be worth downloading for future reference. Should the need arise, you can then check it is being used correctly on the bus.
I've been under the impression that their knees need to reach the seat edge before the booster can go away? Do I have that wrong?
You are correct. To pass one part of the Five-Step Test, the child’s knees must bend comfortably over the edge of the vehicle seat cushion. The five step test can be viewed in detail
here on carseatblog.com.
My concern about using it in the car is that he gets no head/neck support from our van's seats.
When you say “no head/neck support” from the van seats, do you mean there are no head restraints fitted? Or, if there are head restraints fitted, his size is such that they are of little or no benefit in terms of providing support?
I understand he rides in a Britax Frontier using the 5-point harness and also that he uses a booster. Does he lack support in both seats or just one?
He's really small for 8, and he has low muscle tone...I want him to have good support, especially on long trips.
The E-Z-On Vest is very supportive when fitted and used correctly. However, if he requires head support, then you may need to consider other options.
While I am by no means an expert, I think there are two main factors to be addressed.
First, I would consider the continual unbuckling of the harness or seatbelt. If possible investigate why this consistently occurs. It could be linked to a lack of support or it may be a sensory or behavioural issue. If it can be addressed you might not need to purchase a new seat. However, if the issue persists then I would consider looking at the Merritt Manufacturing chest clip and buckle guard as
Ketchupqueen and
DCBINDY have recommended. Details can be found at
www.escapeproof.net.
Second, I would think about support needs. Does the Frontier provide adequate support? If not, what seats could provide this support? I think his size and weight is a benefit in this case – you are able to choose from regular seats as well as special needs seats. It is generally recommended to consider regular seats before special needs seats/restraints; they tend to be less expensive and there is a much wider choice.
If you do consider special needs seats, don’t forget to research the accessories available for each seat. Some have positioning wedges and extra foam supports approved for use with the given seat.
On a different note, if your van does not have head restraints fitted, please be aware those seating positions which lack head restraints are unsafe for any occupant as they would be at risk from neck/spinal injuries in the event of a crash or impact. If necessary, I would aim to address this as soon as possible.
I hope this helps, if there are any other issues I’d be glad to try and help.