Do cigarette outlets in cars now support accessories without draining power after the car is turned off?

I was looking to hardwire a radar detector in my 2017 challenger because when I had a 2011 Buick Regal, I left my radar plugged in and my car didn't start one day. I think it was because the radar was drawing power constantly.When I spoke with a geek squad member, I asked if his hardwire process involved using an accessory cable to prevent constant power while the car is turned off. He said that he taps into the cigarette outlet and claimed that cars nowadays automatically have accessory support in cigarette outlets.I'm not too tech savvy so I was hoping someone could chime in. Is it safe to leave my radar detector plugged in always into the cig outlet while my car is off? Or should I hardwire to make sure that doesn't happen? It's a bit inconvenient plugging and unplugging it every time I get in/out of the car.Thanks! via /r/cars http://ift.tt/2uvL15z