Tesla Model S Autopilot
Autopilot takes control of the steering, accelerator and brakes of all new Tesla Model S and Model X carsReuters

Tesla Model S drivers need to stop doing crazy things with the car's Autopilot self-driving feature, says company boss Elon Musk.

The chief executive said the company was planning to add additional constraints to the car, which would be used to "minimise the possibility of people doing crazy things with it".

Musk didn't say what the constraints would consist of, but they could instruct drivers to keep a loose hold of the wheel more often, and prevent the system from being used on roads other than motorways.

Concerns were raised after a number of YouTube videos demonstrated how Autopilot failed to work on single-lane roads, where Tesla warns drivers against using the system.

The news came as Tesla announced positive results for its third financial quarter, including a record of 11,603 deliveries of new vehicles over the three-month period, and that the Model 3 would be revealed early in 2016.

Musk also said the company would look to make acquisitions if this would speed up the new car's development.

Less encouraging news came from the new Model X, as Tesla admitted it had struggled to get hold of enough of the car's second row of seats, forcing it to begin building them in house.

Model 3

As for the Model 3, which is expected to cost from £25,000 and be aimed at the mid-sized market dominated by the BMW 3-Series and Audi A4, Musk said it would be revealed to the public in March 2016.

A release date hasn't been confirmed, although 2017 looks likely, and Tesla has denied claims that it could slip to 2018. This would not be a surprise, however, given how the Model X missed its original release date by two years.

To help bring the Model 3 to market on time, Musk said he was open to the idea of buying out companies whose skills and position in the automotive market could help Tesla.

In its 12-year history, Tesla has only made one acquisition – Riviera Tool, a US car suppliers, which it bought for $10m (£6.5m) in May 2015.

"Anything we can do to tighten that time frame organically, as an acquisition, is a good thing," Mush said.

"The crazy thing is that $10m we spent acquiring Riviera was less than we spent expediting our stamping dies [tools to shape metal panels], so it's like a no-brainer [to make similar investments]."

A hands-off problem

Musk's Autopilot comments address the "hand-off problem" outlined by Google in relation to its own fleet of autonomous cars.

As part of its October monthly report, the search giant found that drivers were bad at taking back control of semi-autonomous vehicles, stating: "Some participants took up to 17 seconds to respond to alerts and take control ... there's also the challenge of context – once you take back control, do you have enough understanding of what's going on around the vehicle to make the right decision?"