They should be able to calculate the speed based upon where the vehicle hit earth again.
The displayed speed is calculated through the transmission. If the driver held the accelerator to the floor while the driven tires were not touching the ground the vehicle could have easily been spun up to 90 mph.
Perhaps the driver confused the accelerator pedal with the brake pedal. Just throwing that out there for consideration . . .
True. Simple ballistics.
Here is where they landed. Looks very close to the bottom edge of the cliff. Probably only had to be going 30-40mph to make it that far.
They might have rolled down part of the cliff.
Here's the cliff.
Death plunge vehicle's speedometer 'pinned' at 90 mph, authorities say
Be aware the 'pinned' is not the same is 'pegged'.