The history of pushbutton starting in modern cars...
Early engines with distributors and carburators could start in a partial turn of the engine if everything was right. Very short crank times.
Later as engines got computerized the computer actually needed to know what cylinder was where and sometimes even what stroke that cylinder was on. This lead to some extened crank times on some engines. 4.0L Jeeps are real bad.
About 13 years ago Chrysler put a lockout on the starter solenoid so it would not engage when the engine was running. They were having issues with old people grinding the starter down trying to start a running engine.
Later the OEMs started putting an interface between the key and the solenoid. Chrysler had the patent on the running engine interlock, so others found that if you let the computer decide if the engine should be cranked or not it did the same function as the Chrysler patent, but since the logic was different it was not a patent infrindgment. Sometimes you can tell these systems as when you turn the key it take a fraction of a second before the engine starts cranking over.
The next eveloution was to let the computer control the engine cranking. This did wonders for reducing the complaints of customers on "long crank time". You just touch the key and the engine starts, no more releasing the key just before the engine lights off and having a mis-start. This also works good at preventing the pre-cats from loading up on fuel as they are getting more aggressive and getting placed closer to each cylinder.
At this point you are at the point that the computer completely controls the starting of the engine.
Anoter leg comes along, the key fob. For years it was a handy pushbutton way of unlocking the doors. But in the past few years they got smart. No longer do you even need to remove the key from your pocket. It is a very low power radio reciever/transmitter. Range about 3 feet. (the conventional keyfob is still there with its standard range as well). When you are close to the multiple antenna on the vehicle it senses the key/fob and will let you unlock or lock the door. If it senses the key inside, push the button and it starts the engine.
That is the history of the modern pushbutton starter.
Now the old school pushbutton starter. Like most race cars. Toggle switch for the ignition (and other features), push the button and the engine cranks over. Sometimes they will even wire the starter so it will work without the ignition, handy for bumping the engine over during maintance without starting it. IT is done as it is simpler then an ignition key. Simple enough you can't loose the key either. Security is not very relevent, you don't park your race car at the mall.
