Car Stops - The Need to Wear a Seatbelt

We all know that cops are not legally required to wear seatbelts while on duty, for some very good reasons.  We also know that a car stop can get ugly very quick.  However, sometimes it makes sense to put your seatbelt back on when you return to the cruiser to do paperwork.
It seems that everyone knows an officer whose cruiser was hit during a car stop.  Your cruiser with the lights on becomes a magnet for drunk and negligent drivers to run into.  If you are conducting a routine car stop and you are writing a summons, you have 20-30 feet between you and the car you stopped.  If you see the driver’s door open, how long will it take to unbuckle and get to your weapon?  If you see the lights in your rear view mirror, how long would it take to put your seatbelt on? 
What happens to you in a rear-end collision?  You get thrown back in your seat.  If it’s an off-center impact, you get thrown back into the corner of your seat.  Your seat then acts like a spring and throws you forward.  If you’re strapped in, you don’t become a human projectile into a computer, printer, shotgun rack speed gun, dashboard or steering wheel.  This might become a life or death decision.