I just had two keys made. Did not have to go to the dealer. I bought two transponder keys off of Ebay for $6 each, the shipping was also $6. So, $13 per key I thought was a pretty good buy. I located a Locksmith who would cut and program each key for $50 ea. So, I into two keys for about $125. I thought that was pretty good, maybe there are better deals out there. The locksmith plugged into the cars computer (not sure what he did) but he had to wait about 10 minutes before he could program the keys. I have an 02 GT vert with PATS2. I only had the one key. I have been told with PATS2, you must have at least two keys before you can program them yourself.

Hope that helps.
gjt