The narrow bit of space, that's located between the driver/passenger seat and the centre console.
You're in the car driving along with a friend, and they can't find their phone.
Friend: Have you seen my phone? I've looked everywhere!
Driver: Uh oh... it's fallen into the crevice of doom!!!
Both the friend and driver agree that it's easier to buy a new phone, than deal with effort/pain you need to retrieve the phone from the crevice of doom!