Tesla CEO Elon Musk said that he wants his company’s cars to offer custom horn and movement sounds in the future, and suggested that these could include the sound of goats, farts, and even coconuts. Teslerati notes that this latter suggestion seems to be a reference to King Arthur in Monty Python and the Holy Grail, who has his assistant Patsy use a pair of coconut halves to imitate the sound of his absent steed.

From September next year, electric cars sold in the US will have to emit artificial noise when traveling under 18.6 miles per hour, to make up for the absence of noisy internal combustion engines. Electrek reported that Tesla started adding this sound to the Model 3 last month. The US National Highway Traffic Safety Administration recently proposed new rules surrounding the feature that would allow drivers to choose their own vehicle sounds.

& sounds too (also, of course) — Elon Musk (@elonmusk) October 6, 2019

Tesla might have a harder time introducing the new sounds in Europe, however. The EU’s rules, which are due to come into effect in 2021, specify that an electric car’s fake noise “should sound similar to the sound of a vehicle of the same category equipped with an internal combustion engine.” Sounds like that rules out coconuts then (sorry Arthur).

After his initial tweet, Twitter users were quick to suggest other sounds that Teslas could come equipped with. One Tesla owners club suggested “jungle and rainforest sounds” (“Sure” was Musk’s response), and another user asked if Tesla cars could one day let users upload their own custom sounds (Musk said he’d consider it).

Regulations around what car horns should sound like, meanwhile, seem a little more flexible, at least in the US. Although they vary from state to state, many say that a horn sound is okay so long as it’s audible from 200 feet away, and can’t be “an unreasonably loud or harsh sound or a whistle.”

The arrival of mass market electric vehicles means that many of our old assumptions about the way our cars look and sound are quickly becoming irrelevant. Goat and coconut sounds might be a lighthearted suggestion for the future of motoring, but this is the future we could soon be faced with.