The track area where the wheels ride is built up slightly compared to the rest of the deck. If the spot where the wheel "touches down" was on the main trailer, I don't think there would be the vibration. Essentially, though, the touchdown point is on one of the two panels that fold out from the main trailer.
I spoke to one of the ride ops at the FSF, and they appeared to be aware of the vibration, and noted that they had the jack stands tightened down as much as possible.
As far as the underside of the cars go, there is the previously mentioned airbag (similar to the air ride suspension on some trucks) as well as what looks like a shock absorber. Long term, I have to believe that the vibration will be a problem.
Overall it's a nice looking ride, has a decent capacity, and appears to be reasonable to set up. Of note, I spoke to a Majestic representative at the trade show, and they are marketing this as a family ride.
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"Faith is taking the first step, even when you don't see the whole staircase." - Martin Luther King Jr.
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