The strategy mentioned is booking the car for a short period and hoping for a better car. Once you're off the lot, calling to extend it. The problem is that the rate can change and be drastically different than original.
Originally Posted by
rtch92
they wouldnt be losing a car if it's a short rental, so typically they would give it free.
I'd not say it's "typical" that they will give a better upgrade for free. It's more likely that they will give it for free or a lower fee, but far from "typically free".
The poster is trying to get a specialty car on a premium reservation. That's often a stretch even as a Chairman so I wouldn't count on it, no matter the rental length.