Hello all: I am about to buy a 2009 Prius. I test drove it today and liked it. However the seller has only one key. I am trying to get him to buy me another key. But I was doing some research on this forum and other places and I am confused as to what exactly SKS refers to. 1. The key that he had was only the fob that I had to insert in the fob slot on Prius' dash board. I thought it did not have any mechanical key but from doing some research I have found that the mechanical key is hidden inside the fob. Anyway the car started with the fob. Is that SKS? 2. I also read that there is a feature that it unlocks automatically and turns on dome light etc if you get close to it. Is that SKS? Is that optional and may not be in the one that I am looking at? 3. Also if I end up in buying the key myself would I have to get it programmed from the dealer. I have found some programming instructions but then apparently they came from some German manual and some people have been able to program them successfully and some haven't been. Besides I was not sure if the instructions will work for 2009 model. 4. Also I have been reading about silver logo fob and black logo fob. Apparently Silver is master and black is sub-key (right?). Does this apply to 2009 model as well. What's it the difference? Sorry for too many questions, but I am really confused. Will appreciate any help. Thanks in advance.