Found this website while browsing around and thought this should be stickied somewhere. They have instructions for most cars out now-a-days, I have provided a link below to the 2003 G35 instructions, you can always search for other years and models. And yes it is completely free.

http://programyourremote.com/classif...Ad.asp?id=1604

http://programyourremote.com

 

nice find..i was looking for one of these

 

This is in the DIY section of these forums, and have been posted various times already.