// Sort Vehicle array retrieved from DB by item order
let sortedVehicles = Vehicle.vehicles
    .sorted { $0.order < $1.order }
    
// Save index to 'order' for each item in array
let reorderedVehicles = Vehicle.vehicles.enumerated()
    .map { (index, item) -> Vehicle in
        var localVehicle: Vehicle = item
        localVehicle.order = index
        return localVehicle
    }