Depends on whether or not the car can 'tilt' while it is moving sideways (I know they don't show it doing so). If it can then any amount of acceleration can be presented as 'up' and 'down' force to the occupants much like a plane.
When combined with the acceleration they are indistinguishable. I got a chance to ride in the full motion simulator at NASA Ames and it used this 'trick' to recenter itself after it had made a left or right motion. Inside you felt nothing, like the system was unmoving but outside it was moving the flight pod back to the center of motion so that it had maximum reach for the next maneuver.
I'm sure the TK folks could manage it. The trick is that the 'tilt' of the car on the linear motor would add an additional degree of freedom to deal with. And yet it would be expensive but they seem to have already crossed that bridge :-)
Less than you'd think, if you design it right. You only need to gimbal the car and make it bottom-heavy. Still more complex and expensive than not doing it, but no computers or actuators are required.
