Ok, did a little research - here is info for posterity:
Yes, that cute five-sided indentation is one of a number of distinct patterns, so the keys aren't one-size-fits-all. Our options are:
1. Contact previous owner and hope he has the key. Failing that, order a new key from McGard using the key ID code, by ...
2. Search glove compartment for a little card (or hope previous owner has) which has the key ID code.
3. Go to Nissan dealer. They should be able to discern the code using a master key they should have.
4. Failing all that, send McGard a photo of the face of the lock, along with some other info (call them at 800.444.5847 for full details).