Bill, at least on my Prius, that mechanical key will open the driver's side door, but will not start the car.  There is no mechanical ignition lock, just the slot to insert the electronic "key" if one prefers to use that rather than the "keyless" ignition system.  So far as I can tell, that keyless ignition system is the one shortcoming of the car.  I too do not like the price tag for replacement.  The high cost is in part to reprogram the wireless receiver so that the lost key will no longer be recognized.  However, that task could be as simple as it is for a garage door opener, if Toyota were thinking of the customer's welfare.   And, they charge the full price even if no key was lost, but one just wants a spare.  My dealer quotes $198, not $300, though.  Still too much, but maybe that's what has kept me from losing a key.  mcneely

---- Bill Witz <pbwitz@SBCGLOBAL.NET> wrote:
> Funny: you did know that your FOB has a key inside it to open the door and
> start the Prius? At least on our 2008 which is as  comfortable as our Vanagon
> with the recaro seats I installed(thank you Mr T)
> But it does get 48 MPG without much effort on our part. No I do not think this
> one act will save the planet.It is just a small step.

--
David McNeely