I saw a video of a guy that adapted the Lexus unit to his C5. To start the car you must have the brake pedal depressed or else it just turns on the ACC. Myself, I like turning a key, but I won't complain if my next car has a push button start.
Would be cool to have a remote for the push button start! Then you could start your car when standing behind it to take in the awesome sound....almost if you could have your car start at will or command it to start... someone should think up such a device....being able to command start the car would be cool. I think they should call it go-start!