Backordered doesn't mean that the parts don't exist. It usually means that the referring warehouse has nore orders than inventory. They're trying to get caught up and might refer your order to another warehouse or might sit on your order for a day or so because they know that they have more coming in.
Best case order- the warehouse has it.
Next best case order- a warehouse farther away will ship it.
Best case backorder- "in transit," where the warehouse knows it has some inbound and waits for them.
Next best case backorder- there aren't any in the pipeline, so your order gets referred to a warehouse that has the part.
Next worse case backorder- every warehouse has backorders, but the pipeline can largely keep up with demand (it just can't maintain warehouse inventories).
Worst case backorder- "intergalactic," where every warehouse has backorders and the pipeline is dry.
The word "backorder" covers a lot of ground, and a recall makes for a sudden spike in demand for a part.
VOR isn't an overnight shipping order. Ordering something overnight means that some warehouse has it and you're willing to pay through the nose to get it shipped overnight. VOR means Vehicle Off Road, which is a high priority order for a backordered part. Unless the first part available is going to your local warehouse anyway, it will involve overnight shipping- it just doesn't mean that the part will be in the day after the order is placed. That can't happen when none of the warehouses have it.
To save all that talking, you'll just get told that the part is backordered and you'll get a call when it's in.