The latest hidden 'Easter egg' to be discovered by a Tesla driver sees the car's charging port turn into a glowing rainbow. The gimmick, which activates when the release button on a Tesla Supercharger is pressed 10 times, is one of a growing number of hidden tricks to be found on Tesla cars.

Discovered by Kevin Schreiber, who posted a video on YouTube to show how it works, this Easter egg joins a growing number of software features hidden inside the Tesla's ever-updating firmware. Another recently added trick turns the Model S's dashboard readout of the road ahead into a multicoloured lane inspired by the Rainbow Road track from the Mario Kart video game.

Tesla chief executive Elon Musk refers to these pointless-but-fun features as 'cowbells' and recently promised that the upcoming Model 3 car, due on sale in 2017, would have "more cowbell" than any Tesla to date.

Other hidden features include a way to change a picture of the car in its suspension ride height menu to one of the Lotus Esprit submarine from the James Bond film The Spy Who Loved Me.

More cowbell

Another Tesla 'cowbell' gives a nod to the The Hitchhiker's Guide to The Galaxy book series by automatically renaming the car 'Life, The Universe and Everything' when you give it the name '42'.

Software gimmicks like these help to separate Tesla from the rest of the automotive industry and make it stand out not just by offering fast electric cars, but by having a sense of humour and a personality – something that can't be said for enormous car makers such as Volkswagen Group.

This act would be difficult to maintain, however, as Musk has plans to grow Tesla from a company making 50,000 cars in 2015 to one producing 500,000 annually by 2018 and a million annually by 2020. This huge increase would be required sooner rather than later, as the new Model 3 earned 325,000 pre-orders of £1,000 ($1,000 in the US) in just seven days after it was revealed at the end of March. Musk says the first Model 3 deliveries are to begin in mid-2017.