Well, I used it. I knew, as a mother to a shy 3 year old and a rambunctious 1 year old (2 on Friday!) boys, that the opportunity would present itself, more likely sooner rather than later.
This morning, I dropped DS1 off at preschool and took DS2 grocery shopping. After shopping, we got back to the van where I KNOW I buckled him in. I was on the cell and had to hang up to get the dang-darnity thing clipped. I double checked it. It was latched.
A few miles down the road, as I'm going 45 mph, I hear DS2 making a strange noise. Look in the rearview mirror and he's standing on the seat, unbuckled, scared half to death. I fight the impulse to slam on the breaks and I put on my hazards, slow down, and look for somewhere close to pull off the road. The nearest place happened to be a gas station.
I pull in, put the van in park, and go around and open the door. Behind me, I hear a woman gasp and say "You're a filthy (expletive) to let a child that young ride without being buckled in." I looked over my shoulder, gave the look of ice and said... "What an interesting assumption." Turned back to DS2, lectured him about not undoing his buckle while Mommy is driving, buckled him back in and off we went.
I was so happy that I remembered to use 'the line' that I almost forgot how scared I had been!
**Edited because my subject line had included what sounded like a brag, so I removed it :0