I have a 2019 CX-5. I was able to transport a capcom pinball magic just fine from Ohio all the way back to New Jersey.

It was tight going in, but once situated, there was plenty of room to spare. The capcom cabs are slightly taller than WPC cabs, so it should be easier to fit in a Williams/Bally game--though I haven't tried yet.

I wouldn't expect a Gottlieb System 3 game to fit unless you put it in sideways. The cabinet is just too deep. Much deeper than a capcom.

I was able to fit a system 11 (Taxi) and a Capcom (pinball magic) in my 2019. The capcom cab has similar dimensions to a Gottlieb System 3, so it needed to go in sideways. But the Taxi slid right in without an issue, and about an inch or two of room to spare. I use harbor freight moving blankets between the head and cab before strapping it down.

2017 was the year it was redesigned, so 2017 to current (2021) are all the same. There’s enough room to fit a game. Seats fold down nearly perfectly flat.