Car Talk Puzzler

I'm having a car problem that feels the same size and shape as a Car Talk question, but with no opportunities to ask Tom (RIP) and Ray, I've decided to bring it to the hive mind.

I have a 2005 Camry with standard equipment. I'm down to one key -- the others have gone missing over the years, though I suspect one is still in my house. I do not have keyless entry or those RFID chips in the keys that verify your key when you try to start the car. Just flat metal cut to a shape. About a year and a half ago, my key started to have some trouble unlocking the passenger door. A little hitch at first, then you'd really have to waggle it to get the lock to turn, then nothing. I thought it was something with the lock, that I should get it serviced. But when a service place told me it'd cost on the order of $90 to even diagnose, I decided I could live with unlocking from the driver's side only.

I came to recognize that the problem was not with the lock but with the key. Part of this was because while the key couldn't unlock the passenger door, it had the same problem in locking the driver side door. Incidentally, both of these tasks require you to turn the key counter clockwise. That doesn't make as much sense if it's a problem with the lock, but a metal key's sharp edges, and its peaks and valleys, abused over time by years of metal-on-metal friction (as well as occasional off-label use as an ad hoc box cutter), could get worn down and no longer align the tumblers properly. More recently, in the last couple of weeks, I started having problems unlocking the driver's door and the trunk. My positions of laziness and cheapness were no longer tenable.

You can't just copy a worn key without getting a worn copy. So I looked into getting a worn key fixed, and called the dealer. Walser Toyota, where I bought the thing nine years ago, told me that if it's a plain metal key, they can re-code a new key that would essentially restore its factory pointiness and sharpness. They'll do it, for about $5 a copy, if you show them your title and ID. (That price is only good for plain old mechanical keys. If it's a chipped key, it's $68 a copy, and more if you have a built-in remote entry fob. I miss keyless entry, but this is a pretty great feature of low-tech car security.)

So they made me some copies. Their long edges are all sharper than the original, which you'd expect since the cross-section of a blank key will always be nice and rectangular. I was surprised, though, that the teeth of the new keys seem just as rounded-off as the original. Anyway, here's what I've ended up with:

• KEY 0 (or, if you prefer, KEY PRIME) - the last surviving original. Unlocks driver, locks passenger, unlocks trunk, starts car. Exterior lock performance is hinky, as described above.
• KEY A - new copy. Locks & unlocks both doors and trunk, starts car. Turns the locks more easily than I think any key ever has. Locks the trunk so it can't be popped from inside the cabin, which I don't think I've ever tried. The King of Keys and Key of Kings.
• KEY B - new copy. I think I got this one to unlock the driver door once. Does nothing else. Worse than the original.
• KEY C - new copy. Worthless garbage. Might as well be for another car, for all it operates on this one.

To look at them, Keys A through C seem identical. After I discovered their surprisingly diverse ability levels, I went back to Walser. They were stymied, but wondered if it was a problem with the locks, and sprayed in some rust reducing agent to take a stab at it. They say if that doesn't do it (it didn't), I should come back sometime. But the locks obviously aren't the problem, right? If it were, one of the keys they made me would not have been the One Key to Rule Them All, and I'd be having problems with all of them, right?

So, dear people who might know more about cars than I do, what now? Was Walser giving me crappy copies of my old key, instead of grinding a new one to the factory code? If so, why is one so much better at its job? And what do I do now? Take it to a different Toyota dealer? Call a locksmith? In short, what the hell?