[TXcarguy]

how close do you have to be to start the car?

You pretty much have to be inside the car with the key before it will start (with the Advanced Key feature). There have been many occasions when I was standing outside the car and wanted to demonstrate the DRLs to people by turning on the ignition (which is achieved by pressing the "start/stop engine" button once). Well, I found that with the key in my pocket, simply leaning in to press the button while standing outside the car doesn't usually work. So, I often have to lean WAY in... to the point that my waist is inside the car. The sensor is quite sensitive.

 

[TXcarguy]

A TSB has come out for this issue. See this post.