Dual vs Mono Tube Wheelchair

I had an evaluation for my new wheelchair today, my first custom one. It's going to be the Tilite Aero T. I chose dual tubes because the woman I met with said they were a better ride, lighter, and made for better stability. When I asked her if they could still easily sit on a seat in the car she said yes because the second bar tapers off, but from what I've looked into since she left, everyone is saying the opposite. I'm weighing my priorities and if I should call back while it's still soon enough after and ask to switch to the mono tube because that was also an option on the same chair.

If you have dual tubes, what is your experience with loading it into a car? Do you have to put the frame on the passenger seat/does it have to sit ON top of whatever seat you put it on or is it able to fit nicely slotted over the seat the same way a mono-tube one does?

I attached the example photo she pulled up for me when we were talking.