I lost my spare key. Found one on line, looks identical, even though it is from an IS. Dealer says that once the key was programmed, it cannot be reprogrammed to use with another vehicle. I smell a lie, as I'm sure they want me to get a new one. Also, dealer played a bit of a scare tactic on me saying that if I lose my only key, I will need a new computer module costing thousands. How much of this is true? Should I bite the bullet and get a $500 key that will sit in my drawer?

 

Well, we've had members reprogram keys from ebay and others that say it doesnt work.
Adding a (new unused) key is something most dealers commonly do.

The few that have had it done say that you just need to master reprogram all the keys if bought used (ebay).