I believe this was the ad that either won or was a finalist in the Doritos make a commercial contest, and I like it.

It's a rather simple premise: guy driving around eating a bag of Doritos and is distracted by a cute girl, gets into an accident, cute girl comes to help him, she falls. They use words like "crunchy" and "smooth" to highlight what's going on in the commercial.

If you can't drink and drive, this commercial shows that you also can't Dorito and drive.