I had just picked up a rental car to use during a work trip, of a make and model I'd never driven before. Just as I pulled out of the parkade onto the road leaving the airport and the speedometer moved above the 10, the car shook and a made a sound that had me frantically looking in the rearview mirrors to see what piece of itself the car had just dropped on the road behind me.
Nothing. The road was clear, the car wasn't shaking or making any funny noises anymore, and was accelerating smoothly. Weird.
Just as I pulled off the airport road onto the freeway, and accelerated further, it happened a second time. This was really weird. Still nothing on the road behind me.
It was probably 5 minutes later, as I was driving around a 270 degree freeway ramp to get going the way I wanted, that I figured out what the noise and vibration was. Something not visible inside the rental car parkade, and not in my line of sight when driving the car due to keeping my line of sight on the road.
Impeccable timing on that thunder, Mother Nature.
I'm glad the funny noise wasn't a sign of anything damaged or about to fail, but I've encountered those conditions more than a few times. One reason I pay attention to them!