What is the difference between master key and valet?
 

Sounds like a stupid question. I only have the valet and I was curious about what made them different (i.e. not working in the trunk lock). Is it like an extra tooth or something? Also, is it possible to convert the trunk to use the valet key without rekeying it? Thanks.

Like BMW's, the valet key will not operate the trunk or glovebox or anything else keyed except the doors and ignition. It shouldn't even unlock the gas tank.

I don't know about rekeying.

valet key
 

Yes, something different in how valet key is cut, I presume to preclude a valet from searching glove box and trunk for valuable's. I'm guessing, but don't know, that a valet key cannot be recut (remove material) to open both ignition and trunk. That is, the valet key is missing material, so even making an impression still leave's a difficult problem in cutting anew a bunch of keys made from a valet impression and probabilistically finding one that works (a large # of keys). I'm no locksmith, this is just my guess.

There are three different "keys" , the master key, the wallet key and the valet key. the remote key master key and wallet key are identical except for the shape of the head. the wallet has no head, the valet will only work in the ignition since it it is missing the groove in the middle and has a round head, I dont think it works in the door, it does not work in trunk or glove box. I immagine you could cut a groove down the side (s) but for $15 why would you!