Tesla Model S
The Tesla Model S contains several fun 'Easter eggs' in its softwareReuters

Elon Musk loves cowbells. Better known as Easter eggs or fun hidden features, the Tesla Model S has a number of cowbells programmed into it for owners to seek out and play with.

They might be pretty much useless, but that doesn't stop them being fun. Here are five of the most popular we have found so far.

Mario Kart Rainbow Road

The latest Model S Easter egg turns the Autopilot self-driving interface into the Rainbow Road track from Mario Kart. By quickly pulling on the Autopilot stalk four times in quick succession - instead of the usual two to switch on autonomous steering and braking/accelerating - the digital road showing the car's lane position changes from grey to rainbow-coloured. Switching lanes transfers the digital car to a new rainbow road.

As the colourful road scrolls by, a brief snippet of the Blue Oyster Cult song Don't Fear The Reaper plays. This refers to a segment of the song which was played on the TV show Saturday Night Live during a sketch with Will Ferrell and Christopher Walken (playing Iron Maiden frontman Bruce Dickinson) who says the song "needs more cowbell". Musk also recently tweeted to say the upcoming Model 3 would have "more cowbell" before it goes on sale in 2017.

Warp speed

Cars fitted with the Ludicrous Speed mode not only get a 0-60mph time of 2.8 seconds, but they also get a fun little Easter egg. In the acceleration menu, press and hold the Ludicrous option for around five seconds, then the entire screen fills with streaks of white light similar to warp speed from Star Trek or when the hyperdrive is activated on the Millennium Falcon.

James Bond Lotus

In October 2013, Musk paid over $600,000 at auction for the Lotus Esprit submarine used by James Bond in The Spy Who Loved Me. He said he planned to fit the vehicle with a Tesla electric powertrain and make it actually work as an amphibious car, but nothing has been seen of it since.

While we still wait for that car to become reality, Tesla owners can have some Bond-esque fun of their own. A long press (between seven and 10 seconds) of the Tesla logo at the top of the dashboard screen opens a text box asking for an 'access code'.

This is usually where a Tesla engineer would enter a code to gain access to the car's operating system, but if you enter 007 and tap OK, something else happens. Head to the car's suspension settings (only available in a car with the optional air suspension fitted) and an image of your car has been replaced by the James Bond Lotus. And where you could previously adjust the ride height, you can now pick from a depth ranging from zero to 20,000 leagues - 20,000 Leagues Under The Sea being a film from 1954. Reset the screen to bring back the standard suspension menu.

Meet Tesla - and watch your car drive away

Tapping the Tesla icon at the top of the dashboard screen brings up an information panel about your car. This includes the exact version of Tesla you own, its mileage and the current software installed. There is also an image of your car in the corresponding colour. Press and hold the model variety - 70, P90D etc - then after a few seconds the car speeds off to the left of the screen, revealing a photograph of Tesla employees waving to the camera.

Discover the meaning of life

If you change the name of your Model S to 42, it automatically changes this to Life, The Universe and Everything - a reference to The Hitchhiker's Guide To The Galaxy.

With the Model S and new Model X getting regular software updates while they're parked up at night, we fully expect Musk and his team at Tesla to install new Easter eggs or cowbells over their lifetime of both cars - and of the Model 3, too. They might not add any functionality or value, but they're fun and that's all that matters.