Diono Monterey 5iST FixSafe High Back Booster Car Seat - Expandable Height & Width, Compact Fold to Full Size, Portable & Foldable for Travel - Black Jet | Perfect for Road Trips, Airplane Travel & Everyday Use

We are another Tesla Model 3 family frustrated when our car seat that was supposed to easily convert from a harness to a belt positioner ended up being too wide to access the seatbelt buckle in that mode. Apparently this new model of the Diono Monterey and the Diono Everett are twonof a very few models of high back boosters that are narrow enough to make the buckle accessible. I went with this one because it looks cool and in case we wanted to travel with it. However, we did still have to buy a 3” rigid seatbelt extender to get the buckle out from recessed so that my child can buckle it herself. My engineer husband was not as concerned about safety of using the extender as I was, but in the end an easily buckled child is safer than one where it’s hard to tell if the buckle has clicked because you need an adults weight on it to make it click. I think the Everett is 0.5” narrower and that may make all the difference and I probably could’ve returned this to get that one. Anyway, so far so good in terms of its comfort, my almost 6 year old (49” and 52 lbs) has fallen asleep in it a couple evenings already. She used to get car sick when rear facing, and we went on a 2 hour road trip this past weekend and she had no issues (I still have blue emetic bags stacked everywhere, though!). It installed fairly easily and feels rock solid due to the rigid latch. There are no arm rests but I don’t think my daughter cares since the previous car seat didn’t really have them. The cup holder does the job and fits her wider Contigo and stainless steel water bottles. We also got the Diono brand cubby/box for her to keep snacks, books, sunglasses, etc. because her old Chicco MyFit had a little box that attached that she got used to having it all close. So far no issues getting her to sit up straight and not fool around with the adult belt on…if we had switched her to this mode a few months ago that wouldn’t have been the case. Much safer in a harness as long as possible, but this one is good when your child is finally ready!We chose this model for the compact fold/straps because we were planning plane travel with driving on the other end for our 5yo who is not mature enough for a bottom seat only booster for any significant distance.The fold is great and compact. The provided straps are just webbing, and There was no way we’d use them for more than a minute. I found some clip on backpack straps on Amazon that were more comfortable, but it sits at an awkward angle. You’re better off using some bungee cords to strap it to the handle of rolling luggage if you’re going very far.We gate checked it for our flights but you may be able to put it in an overhead bin.Since the back does not detach, it’s easy to quickly install and remove from an Uber. I had trouble getting the isofix latch connectors to work in one Uber (Toyota sienna, I believe) but it was a short ride so we went without them completely attached.We also like that the sides of this seat expand like the other Monterey models because my son is tall with a long and wide torso and would likely have cramped shoulders by the time he ages out of a standard booster seat. What I didn’t realize until we got it is that the width expands as you raise the headrest, not independently like the other models.Overall we like it but unless you’re planning some travel that includes Ubers and/or flights where you’ll rent a car or ride with family/friends on the other end, save your $$. We have the $100 XT model in our other car and it functions just as well if you’re installing it once and leaving it there (and it still has the expandable back panel). If your child is average height/weight/build, you can pick something even cheaper.This booster is not only nice to look at but it's comfortable. The seat doesn't have as much padding on the bootie as our old seat but he doesn't mind. The fixsafe latch system was a bit hard to get to pop out at first , I had to really push the button extremely hard to get them to come out. But then the install was a breeze. So easy. The chair itself is quite light which makes it convenient to put in other cars if necessary, it folds completely into itself and makes for very easy travel. It could easily fit in an overhead compartment on an airplane and it comes with straps to wear it on your back as a " back pack ". The cup holder is bigger to accommodate bigger cups and it's easy for my son to put the belt on himself. Overall I'm really happy w my choice. We are a diono family and when my old one was compromised from an accident it was a no brainer I was getting another Diono. We upgraded from a Rainier to the Monterey since my son is getting bigger and taller this seat accommodates up to 63 inches and 120 lbs. So he can be in it longer. Which was a big appealing factor in the decision.My kid loved this seat. It is extremely confortable for him.We have been a family of frustrated people ever since our oldest transitioned to a highback booster because our car (Model 3) has absolutely atrocious design when it comes to accommodating car seats: the rear inboard seatbelt buckles are deeply flush/recessed and have no give. We were using a Graco Tranzitions as a high back booster before (a great seat in any other car and one of the narrower more affordable ones at that), it was still just barely too wide to buckle easily. The Monterey 5 iST is not only narrow, but it has ISOFIX. The cutaway allows for easy access to the buckle so my kid can do it himself without struggle. I am pretty sure some savvy engineers have lived through the hell of the Model 3 and designed this seat with it in mind. THANK YOUI bought another one for my 5 year old and he loves it and we love that it is safeExcellent booster seat. Works perfectly and most importantly it is very easy to install and remove.Feels solid when installed and has great side protection.Fits in aircraft overhead bins.We used it on an international trip and are very happy with it.Areas to improve: the carrying straps are thin and cut into the shoulders because the seat is not light. It would be nice to have a carrying handle on top of the headrest.The use of photo renderings to embellish a cheap looking product is a waste of time for all. I ended up buying the Peg Perego Viaggio Flex 120 licorice for safety, comfort, quality and style.Works awesome. We have tracked with our and it wad so easy. Super quick to switch vehicles too. Overall a great seatQualité excellente.