Afraid to graduate 7 yr old to booster

How old is TOO old to keep a kid harnessed?

I have my 7.5 year old in a Britax Frontier, harnessed. He is 56 lbs, 56.5 inches tall. He has PDD-NOS (autism spectrum, high functioning but rather impulsive).

The ONE time I put the 7 year old in a backless booster (the 10 year old's booster), for a quick trip at a time when the car seats were not installed, he did great on staying positioned. I just don't know if he'd do it consistently, back in the 3rd row of our 05 Sienna, when I can't always monitor him.

Is it reasonable to keep him in the Frontier, harnessed, to the weight limit, or am I being overly protective?

I have a 5 year old who has outgrown his (older) Marathon by height, for whom I have now purchased a Frontier 85 as well. For our second car, I'd love to cascade the 7 year old's Frontier, and have the 7 year old using a less expensive seat or even a booster, rather than buy a FOURTH Frontier for the 5 year old.

(DD is 2.5 and only 28 lbs, still RF in a fairly new Marathon, so that seat will hold her for a long while and so her seat won't come into play.)

ETA: I've been keeping with the Britax family because of our familiarity with install/consistency between the two cars, and because DD was able to unbuckle the Graco clips easily.

There is no evidence that a PROPERLY used booster is any safer than a harness. Proper is the key here - that the child is physically large enough (check!) and behaviorally mature enough. Normally, 7 year olds are well mature enough to handle the responsibility of sitting properly in a booster, with your situation, you know your son's impulse control the best. If you're not comfortable with him having that responsibility quite yet and he still fits harnessed in the Frontier - leave him harnessed.

Oh, and as far as a less expensive alternative to the Frontier for your spare if you decide to keep the 7 year old harnessed a while longer, the Graco Nautilus ($140), Evenflo SecureKid ($130), and Evenflo Maestro $70) are all good choices.

I am keeping my 6 yo DS harnessed in his Frontier for as long as possible - for exactly the same reason. (DS Dx'd with Aspergers. Impulsive, fidgety, goofy. Still sleeps in the seat. All good reasons to keep him harnessed.) However, we don't have a seat cascading issue.

My neurotypical 7.5 year old is still harnessed because he prefers it. I would be totally comfortable with him in a booster, but since there's no evidence that one is safer than the other, and both options are safe choices for him, I let him choose.

I'm in a similar situation with my about to be 9 year old. He does great in the booster for shorter trips or less often. He's now in a booster part time for shorter trips and in secondary vehicles. His main seat is still the FR85, harnessed. If I were you I'd keep trying him in the booster for shorter trips, preferably when someone can keep an eye on him at first, and see how he does. I understand your fear, I dread the day Aidan gains another 1/2 inch of torso height.

Normally for a kid that age and size, a booster and a harness are both very safe. But with impulse control, if they don't have the self-control to sit still in a booster, a harness is safer. If possible, I would keep both the Frontier and a booster in the car for him to use, and see how he does in a booster (I prefer a highback for kids coming out of a harness). But I don't think there is really a "too old" to use a harness.
I understand your problem, K is very wiggly. I kept her in a harness until just a couple of months ago because I couldn't trust her to sit still. With practice she has become a good booster rider.

My 6.5 year old regularly rode in a harnessed seat till he was 6, w/occasional rides in a booster. He has high functioning autism, and can be impulsive and flat out "defiant" for lack of a better word. But he's doing fine. It took some work.

That said, I have no problem as a parent or tech, with you keeping him harnessed a while longer--heck, keep him harnessed till he maxes out the seat if you want to!

I think buying him a good booster to learn to use in the second car is a great idea--you can booster train him there, when your spouse is driving, so you can watch him.

OR you could buy the younger child a seat like the Evenflo Secure Kid 300 or a Graco Nautilus, for about the same cost as a really nice booster, but way less than the Frontier. When the younger one maxes it out, hand down the Frontier and let the older one use the Nauti as a booster (will work if he still fits it that way).

It doesn't have to be another Frontier.

GL!

henrietta