These Vehicles Do Have Some History With Fuel Level Sensor Problems (In-Tank Sending Unit On Fuel Pump Module).
Sulfur in the gasoline reacts with and erodes the "wiper" (tiny wires) on the sensor arm.
This does cause the gauge to go whacko, but I've not heard of one going whacko with the indicator needle going outside of the normal range that one ordinarily sees. I usually goes whacko between full and empty.
The fuel pump module / fuel level sensor should be accessible on the trunk floor just ahead of the spare tire well to the right a bit. A small oval panel with a half dozen screws covers the access hole. I'm wondering if there's a way to unpug the harness there and check electrically, somehow.
One need not replace the whole fuel pump module (but, it must come out) as some will tell you. It's possible to replace just the level sensor (sender) or even just transfer the wiper piece from one.
Sorry I can't help more. Maybe some of the more electrically inclined can tell how to test this baby.