There are 3 doors (that includes the hatch) giving access to the vehicle with a key. If none of the locks are working that is definitely uncool. I always use the plip with the master key attached and also always carry a spare key in my wallet, so I won't be locked out that easily. All my locks work with the keys. Hmm. A bit OT perhaps.
Anyway, if anything happens to your plip, drop it in a puddle, step on it, batteries suddenly dead, you are in real deep you-know-what