I was surprised to hear them talking about the "firewall" as part of the construction of a car. I figured that "firewall" as a computing term had to be named for something more physical, but I never would've thought it referred to a piece of a car.
I'm surprised you didn't know the computer term came from a physical world origin! As a WWII airplane buff and son of a fighter pilot, I've been hearing the term since I was a wee lad, referring to the bulkhead that the engine is mounted to. Meant to, you guessed it, try to keep an engine fire away from the pilot and gas tank.
In fact a colloquialism for suddenly going balls-out full speed was "Firewall it!
" Meaning shove the throttle lever forward toward the firewall.