May I suggest a visual aid for their impressionable teenage minds. Something light and friendly that will help them remember what happens to people when two cars collide at high speed.
If I was you....I'd get a dozen cornish game hens, let them thaw in the sun for 3 days, then squirt catsup and tabasco sauce inside them, and fill balloons with a raunchy Maddog 20/20 wine & stuff those inside the bird carcass.
To simulate a windshield, set up some panes of glass, right in front of the kids. If they seem to be drifting off, or you just wanna make a point, throw one of those birds, and I mean a rocket, right through the glass. Throw some stinky wine balloons at the kids too.
I find that yelling, "This is what happens when you and your underage shit for brains friends get drunk and get behind the wheel of a car!" makes some kids vomit....which is better than applause.
A loud audio of babies screaming really adds something special to the presentation.
That's what I'd do......just a suggestion.....
Send me your email address and I might be able to send you a more conventional story of drunk driving.