The chief executive of British sports car maker McLaren Automotive has told CNBC that it would be "insane" for the United Kingdom and European Union (EU) to fail to agree a deal on Brexit.

Mike Flewitt said he spoke to U.K. Prime Minister Theresa May on a conference call two weeks ago and he is confident that a withdrawal deal will be done. How to maintain the frictionless movement of goods between Ireland and Northern Ireland after Brexit remains a sticking point in negotiations. However, the supercar executive warned that any outcome that slowed the cross-border movement of goods would be hugely damaging.

"It would be insane, both for the EU and for the U.K. to run into a situation where we're affecting imports and exports through that period," he said, before adding "We shouldn't let ourselves run into a problem like that in this day and age, it would be crazy."

Flewit stressed that he was not only talking about disruption to the automotive industry.

"Think of food stocks and livestock and anything that's coming across borders being delayed (that) would be a real problem so I'm in the camp of optimists who think we'll find a way through," he told CNBC's Julianna Tatelbaum at the firm's headquarters just outside London.

McLaren officially opened a new composite factory in northern England on Wednesday, allowing it to directly design and build the carbon chassis of its cars in the United Kingdom. The McLaren Composites Technology Centre (MCTC) has been completed thanks to a £50 million ($64.6 million) joint investment with Sheffield City Council.

Flewitt said that decision, while not Brexit related, would help the car maker's control over manufacturing as it moved more production "onshore."

"It actually moves our U.K. content up from around about 50 percent to the core by value, closer to 60 percent," he added.