Help - Bubble in tin at highway speeds

Keep in mind that you don't have to get anything under there to cause it to raise at highway speed. The air moving over it has less pressure than the air under it so lift is created. The only thing for sure is that area isn't being held as solidly.
It's the same thing as when we see a rubber roof ballooning while traveling down the road. It's not that air is getting under there, it that the air moving over the top is moving faster.