A recent update to the firmware in all Tesla cars (it’s up to version 9.0.2018.48.12 now) added a couple of fun and goofy Easter Eggs for Tesla owners to enjoy even when they’re just sitting in their Teslas. The Easter Eggs are called Romance Mode, Pole Position, and Emissions Testing Mode. That last one simulates farts.
You can pick from multiple fart sounds, including Not a Fart, Short Shorts Rapper, Falcon Heavy, Ludicrous Fart, Neurastink, Boring Fart, and what seems to be a fart randomizer. Interestingly, there’s options for controlling what seat the fart appears to be emitting from, which must use some interesting acoustic control.