For those of you who opted not to pay the extra 20 grand for these features:

Stop following so closely. If you're using your brakes and you're not coming to an intersection or exceeding the limits of engine braking on a downhill- you're following too closely.

Pay attention. Just because you're stopped at an intersection it's not time to look at your phone. Guess where the most likely place to get in an accident is? Pay attention to what's going on around you and how you'll react if need be.

Green means it is your turn to go, but only your own observations determine if it is safe to go. Listen to your old friend Elmer the elephant and look both ways. Every intersection. Every time. And actually look and comprehend what you're seeing, not just go through the motions
Use your mirrors and know what's around you. Cars don't magically appear in blind spots, or disappear after they leave your sight line. 

You don't need fancy safety features. Good sense and responsibility are free.