Seat belts save lives:

I was on highway 119 and just passing the mushroom farm when the big black GMC SUV veered right towards the shoulder.  I became very puzzled until I saw a small grey Toyota car veering from the eastbound lane onto the westbound and smashed right into the side of the GMC SUV.

I was behind the SUV but lucky I do not tailgate and had a lot of space to react, but I could have got hit by the grey car as it was being tossed around and it landed on its side (if it landed on its bottom, I would have hit it!).  The SUV spinned around and ended up a few yards away from the road.

Since I was the only person who witnessed what happened, I suspected I had to stay until the police came and more cars stopped and I saw that the people in the SUV were okay and capable of getting out themselves, I headed to the grey car, the front was completely totalled so I half expected to see a/some dead person(s).  To my surpise, there was only one woman in the carand she was pretty banged up and crying.  We could not flip the car onto its wheel so we got the girl to stand up and she climbed out while we helped pull her out.

Her whole left body was blackened with bruises, but considering how she hit the suv head on, assuming at 80-100km/h she is lucky to be able to walk with bruises and maybe some broken ribs/collarbone.  So clearly the seatbelt saved her life. 

So if you know any friends who refuse to wear seatbelts, this story is a testament from someone who witnessed this in real life.  Another important thing is not to tailgate or drive too close to cars in front of you or you'll be included in the ripple effect.