That is narrower than I expected them to be. But to be honest, I am doubtful that 19.5 inches will work. It'll be close. But I think when installed, the cushions will be high enough that you'll hit your head on the roof.

But I do NOT know for certain. And my car has had floor pan replacements so it's possible our dimensions are slightly different. The only way to know for certain is for you to mock it up...just pull one of your seats and set one of these in the space and see if the mounts even reach the seat mount platform.

Or, if the seats are not available to you, just cut a square piece of cardboard or something that's 19.5" wide and long enough to run the full seat travel forward and backwards, and try to set the board down flat on your seat platform...and see if it reaches.

If it does, I'd recommend you also get a measurement from bottom of seat track bracket (floor) to top of seat cushion, and compare with your stock seat cushion height to see if the seat cushion is too tall.

Also, consider whether it is acceptable for you to have no ability to tilt the seatbacks forward to access the back seats.