Another option, if you can't find a booster that will fit, is the safe rider vest
http://www.amazon.com/s/ref=nb_sb_n...&field-keywords=ride+safe+travel+vest&x=0&y=0
Have you tried out some boosters at babies r us? Some boosters "puzzle" with car seats better than other boosters.
I'm not familiar with the Safe Rider Vest, but it looks like a hassle and I think he'd die of embarrassment at having to wear a harness when his friends don't even use boosters.
It's not so much an issue of puzzling, as sheer lack of seat width in a Civic. With the TurboBooster he has now, it's absolutely IMPOSSIBLE for him to buckle up next to the Radians and even if he could, his booster would be falling over because it wouldn't be all the way on the vehicle seat. Not cool.
It looks like
babysupermarket still has them, though I can't vouch for the site. Will a Parkway fit? Are you using LATCH or seatbelt for the radians?
I got all excited that you'd found one, but I tried to add to cart and it says Sold Out. darn.
I've never tried a Parkway. They are just as hard to find as the FPSV though.
The Radians are seatbelted because the baby is in the middle(only position we can RF) and there is no latch there and other DD is over 40lbs so latch can't be used. I've scootched them over as far as I can too.
How about a Baby Trend Flex Loc - it's a very narrow infant seat.
What is your ds's torso height? would he fit in a Radian for another 6+ months?
Do you have head rests in your car that are at least to the tips of your son's ears when he is in the booster? going backless might be an option.
We do not really want/need to purchase an infant seat, but regardless I believe the Flex Loc is as wide if not wider than a Radian so we wouldn't be gaining anything.
I don't remember off-hand what DS's torso height is, but last I checked he was an inch or less from the belt guide in his current booster(Turbobooster) at the highest setting. He definitely wouldn't fit in a Radian, he's very tall. Given his height, backless will be our only choice very very soon, but even then they are all so darn wide.
Too bad the Monterey isn't available in a backless version. It seems crazy to buy the whole thing with no intention of using the back. That'd be an awful spendy backless booster.
I'm almost embarrassed to be asking, but are the Sure Fit belt positioners put out by Sunshine Kids really really bad?? They say they are "thoroughly crash tested" but are they really? I just don't know what else to do.
http://www.skjp.com/products/index.php?v=detail&cid=19&name=Sure_Fit9752&id=16
Too bad the Clek Oto isn't available in the US. That would probably work great.
Thanks everyone for trying to help!