The only sure way of saving data when disconnecting the vehicle battery is to clip a small auxilliary 12volt lead-acid across the main battery's connectors if you have to change it. Plugging a device into the cigar lighter won't always work for reasons outlined above, and that the designer may have put a current limiter into the supply to the cigar lighter for safety's sake. You can't then put current INTO the socket.
Re. keyfob, my 1996 XJ6's keyfob would lose its data altogether if you took too long changing its little lithium battery. The handbook explained how to reprogram the key quite clearly, and it worked for me. It involved putting the key in the ignition and performing certain steps, like pressing a button three times etc.
Leedsman.
Ps. That one about clipping a 12volt supply to the starter motor if the vehicle battery is dud and you can't get in 'cause all the locks are solenoid -- not bad! I'll have to remember that. Better than breaking in, and cheaper.

 

Ed Martino - The dealer did program my FOB's (2) successfully. I don't know about the issue with the ignition switch. The whole issue with tis is that for the '03 STR a computer is needed that only the dealers and high end repair shops have, so only they can do the re-programming.

 

thats the key in ignition switch door, and if sticks open your get the long error tone from the alarm when trying to arm the system with the remote or the key. this is the same tone as when a door, trunk etc is still open