Try this website:
https://www.thecarcrashdetective.com/3-across-car-seat-guide-html/

They tell you which cars you can do 3 across.

FWIW, we have a Mazda CX-5 and I think we could only do 3 seats with the Dionos, but thankfully, we only have 2 kiddos. Our issue is that no adult fits comfortably back there with 2 seats.

when we had three in harnessed car seats, most mid-large SUVs will fit 3 across in the 2nd row. Once we had one in a booster we had to switch to a 3 row with captains chairs in the 2nd row. kid with the booster seat sat in the 3rd row.

Anonymous wrote:VW Atlas Handsdown or MAYBE Tiguan with a 3rd row seat. Another option is a Crysler minivan; they're pretty nice too.

Compared to other cars mentioned, Atlas would be ranked lowest in terms of reliability. Also there’s greater chance of your small kids dinging other people’s cars.

I’m the Above poster. Hit submit too fast. Keep an eye on the safety manuals for the SUVs. Some say (like Mazda) that car seats can only be in the 2nd row if the seats are all the way back. That creates an issue with fitting a car seat in the 3rd row. Also even if the car seat fits in the third row, will your kids legs fit? Kids legs stick straight out while in the car seat. They don’t tuck nicely under the 2nd row seats, like an adult or older child’s legs would. Lastly, will be be easy or difficult for you to access the 3rd row to buckle them in?