The 2012 G37 has a unique rear seat in that the headrest is integral. This is starting to crop up as an issue now that my 5yo son has outgrown his car seat and needs to move to a booster. From my understanding and based on the instructions for my wife's car booster seat, the back of the booster must rest on the rear seat. Unfortunately, with a big headrest sticking out, there is no way for the seat to sit flush. There is a big gap between the car seat and the rear seat.

Also unfortunately in the internet world it's easy search for info on this, but most of it is where the car came out, not 9 years later. And car seats seem to come out every year.

Does anyone know of a current boosterseat that will fit?

 

Are you using a seat booster only, one that has a back, or a convertible seat? The seat-bottom-boosters fit fine. We currently have a convertible seat for my 7-year old and you just have to tighten the snot out of the latch straps to compress the seat foam - then the stock seat belt goes across in the clips to hold the kid in.

 

Well I just returned the booster seat with a back. I think a base only would work but I am concerned about how the seatbelt comes around. The ones with a back have that guide to position the chest strap. How does it work on a Base-only style?

 

The one we use with our friend's kid has loops on the side that hold the seat belt down. Shoulder belt works fine as the booster lifts him up high enough.

I want to say that theirs had a back that was removable, but they haven't needed that part in several years. My daughter is petite so she'll be in a harness booster until she's old enough to not need a booster at all.

 

OP what type of booster seat do you have?

I will likely be in a similar position soon as my 4-year-old keeps doing that growing thing too

 

I currently have a Britax Marathon. but he is past the "Line" on the seat for shoulder height. My wife got the Britax MidPoint Booster, but that seat will not work in my car. I have looked through a few manuals for different seats and manufacturers, and all seem to warn against having a protruding head rest.

As an engineer, I think this really is not so much finding a car seat to adapt to my situation, but adapting the car to fit a normal booster seat. I am looking through a copy of the shop manual, and I might end up removing the back seat, and modifying the foam under the seat material to remove any protrusions. 2.5" of foam to cut off and then any car seat can fit. When I sell the car, I will add the foam piece back.

I will keep this updated if I go down that path.

 

Ok,

An hour ago I decided to take a look at what it would take to remove the foam headreast, and now, an hour later, I completed the whole project. The headrest foam is now gone. I took some photos that I will post here. It was not a super easy task, but easier than I thought. I can now put a regular car seat in.

 

Ok I started taking pics after the seat was removed, sorry. Basically, look where the seat bottom meets the carpet. THere is a little white pullout. Pull and lift. Do on both sides and the bottom seat lifts up and pull out. This photo shows The passenger rear seat removed. To remove the top par tof the seat(The Back), there are two bolts below the seat bottom. The bolts are next to the lower seatbelt mount is. Remove the two bolts and lift up and pull out.

The seat back cover material is held on with little aluminum rings. You will need to bend them open around the top and some of the side.

Here I am pulling back some of the cover. There will be 4 rings that are on the other side of the seat that you will encounter that will need to be cut.

The 4 rings (2 on each side) that need to be cut are located in the seam seen here where the headrest justs out.

If you are lucky, use a electric meat carver to cut the foam flush with the back of the chair. BUT, what you will encouter is a metal frame inside the foam. It needs to come out.

If you slice the foam around there the metal rods are, you can get access to an area where yo can use a bolt cutter or saw to cut them. I used a bolt cutter. For safety, you should cut them as far back inside the headrest as possible so that that no ones head can hit a hidden rod.

Rod and frame piece cut out The rods in the foam eventually go towards the rear and down. You should cut where they are going down. That puts the ends at the back of th chair back.

Reinstalled the seatback

flattened to see the difference.