You shouldn't be able to as there are new end of life directives in place for scrap vehicles.
Once they are drained of all fluids, and stripped of re-cyclable parts, the car is crushed and melted down.
There is an obvious concern, that even with the crushed car, the identity could be stolen and used on a stolen vehicle - I'm not sure if the salvage yard removes the VIN plates before crushing.
You would need to contact a scrapyard directly to see if they will sell you one, but I wouldn't hold your breath.
Stupid question, but why do you want one?