Supernatural Stamina & Vehicles
Your vehicle will return to the battlefield, uncrewed and not a creature.

The first part is because of rule 201.5:


  201.5. If an ability of an object uses a phrase such as “this [something]” to identify an object, where [something] is a characteristic, it is referring to that particular object, even if it isn’t the appropriate characteristic at the time.


Supernatural Stamina is using "this creature" as a flavorful alternative to "this object". :)

Meanwhile, it returns as an ordinary uncrewed vehicle because of rule 400.7:


  An object that moves from one zone to another becomes a new object with no memory of, or relation to, its previous existence. There are nine exceptions to this rule: [None of these exceptions apply here.]


Once it returns to the battlefield, it has absolutely nothing to do with the previous crewed vehicle object that was represented by that same card. It's a brand new vehicle.