Update:
Word from Tesla is "no." Two reasons given: (1) device is not factory tested and approved, and (2) the roadster has a locking column (so it still needs the key).
I have a lease, so I am not doing major aftermarket mods, but for those of you who own, the locking mechanism can be removed and the device installed... but not with Tesla's blessing (so vfx is right, it'll probably void your warranty).