I stock several different variations of that seal for applications like doors, windows, access covers, etc on heavy machinery. As a test, I just went out and held a lighter to the foam bulb side of a piece just to see what would happen. It wasn't like a foam cup that pretty much melts instantly, but rather the opposite. I didn't see anything happen until I held the flame right under the foam itself, and even then it took a bit before it started to burn. Flammable yes, but it actually just smoldered more than anything. My guess is you'd be fine, but it's your car not mine, right?
Did you see the size of that chicken?! -Dirty Steve