This photo provided by TRW Automotive shows a radar and camera systems that warn you, with beeping sounds, of a possible front-end crash is highlighted. The systems are the outgrowth of adaptive cruise control, which came out 15 years ago and helps keep cars a safe distance from vehicles in front of them. (AP Photo/TRW Automotive) by Dee-Ann Durbin and Tom KrisherAP Auto Writers DETROIT (AP) — Cameras that check around the car for pedestrians. Radar that stops you from drifting out of your lane. An engine able to turn off automatically at traffic lights to conserve fuel. Technology that saves lives — and fuel — is getting better and cheaper. That means it’s no longer confined to luxury brands like Mercedes and Volvo. It’s showing up in mainstream vehicles like the Nissan Rogue and Ford Fusion.