3 Across Installations: Which Car Seats Will Fit in a BMW X3?

The BMW X3 is a luxury crossover / SUV that competes with SUVs like the Mercedes M-Class and GLK-ClassVolvo XC60, Audi Q5, Lexus NX, and Acura RDX, as well as with its stablemate the BMW X5, among families interested in a stylish 5-passenger mid-sized SUV capable of safely transporting up to 3 children. You don’t often get the chance to drive a BMW, so when I got to borrow one for the weekend to try out some car seats in it, I couldn’t pass it up. On the outside it looks nice and sleek, and it’s certainly not lacking in amenities on the inside. But what I was really interested in was finding out which car seats can fit 3 across in a BMW X3. The bad news is that there aren’t very many due to some peculiarities in the X3’s seats. The good news is that there are some seats that will work. Let’s take a look!

Before diving into which seats work in the X3, however, it’s always a good idea to review how long we should be using these seats, and which kinds we should be using to begin with. I’m a big fan of extended rear-facing (ideally until 4!), followed by extended harnessing (ideally until 8!), and finally using a booster seat until children are big and mature enough to pass the 5 step test for seat belt use (which typically happens between 10 and 12). Your kids might think they aren’t cool by sitting rear-facing longer, using harnesses longer, or being boostered longer, but to me, nothing’s cooler than my kids being alive and uninjured due to following best practices in car seat safety.

After spending several hours installing and uninstalling car seats in a current and prior generation BMW X3, I’ve got a pretty good idea of which car seats will and won’t fit in one, and feel this is the most complete list of car seats compatible in 3 across configurations with the X3 on the Internet. If you find the list helpful when shopping for car seats, you can shop through my Amazon link below. I’ll add more seats as I test them over time.

You can access the complete 3 across guide for every vehicle here and the complete list of recommended seats here. The Canadian car seat guide is here. 3 across car seat images are courtesy of Wikipedia.

x3 - 2011 - publicdomain2011, 2012, 2013, 2014, 2015, 2016 BMW X3 (F25)

Guaranteed 3 across installations:

Clek Fllo (x3).

Clek Foonf (x3).

Combi Coccoro (x3).

Diono Radian / RXT (x3).

Tips and Tricks:

This generation of the BMW X3 is 183 inches long and 74 inches wide, which you think would mean you’d have a bit more front-to-back room to play with as well as one more inch in 3 across width. However, the truth is that the X3 is a very difficult vehicle to achieve 3 across in. Ironically, it’s actually easier to 3 across in the previous generation than it is in the current generation.

The big issue with the X3 when it comes to 3 across installations is that the middle seat is very narrow. I often found that when I got a seat installed in the center position, I needed part of it to sit in the vehicle seat behind the driver, which essentially made 3 across installations impossible.

I was able to get the Foonf, Fllo, Radians, and Coccoro to fit in the middle while being slightly off center, and was able to squeeze additional seats beside them. Buckle access was very difficult, however.

Keep in mind as well that you cannot use LATCH to install a center seat on BMWs, as it is specifically forbidden in the vehicle manual.

x3 - 2007 - publicdomain2004, 2005, 2006, 2007, 2008, 2009, 2010 BMW X3 (E83)

Guaranteed 3 across installations:

Clek Fllo (x3).

Britax Frontier 90, Combi Coccoro, Diono Radian / RXT.

Clek Foonf (x3).

Combi Coccoro (x3).

Diono Radian / RXT (x3).

Tips and Tricks:

This initial generation of the BMW X3 is 180 inches long and 73 inches wide, which means front-to-back distance is going to be in short supply, but that you’ve got a decent chance with several 3 across installations in terms of side-to-side width. The Frontier-Coccoro-Radian installation works with seat belt installations for the front-facing Frontier and rear-facing Coccoro, as well as with a LATCH on the front-facing Radian. You’ll have more room if you use seat belts for all three seats, however.

Keep in mind as well that you cannot use LATCH to install a center seat on BMWs, as it is specifically forbidden in the vehicle manual.

If you find the information on car safety, recommended car seats, and car seat reviews on this car seat blog helpful, you can shop through this Amazon link for any purchases, car seat-related or not. Canadians can shop through this link for Canadian purchases.