Meanwhile, significant decisions are pending on where major manufacturers will locate new plants, and a Brexiting Britain may not be included in the discussions.

Nissan must decide where to produce its Qashqai model in 2017, Land Rover is mulling where to make the Range Rover Sport in 2017 and Vauxhall must choose where to build all Astra models in 2018.

But the U.K.’s role as a global production hub may help. “At this moment, it is not clear what conditions and rules will ultimately replace the U.K.’s membership (in) the EU, so we will need to carefully monitor developments in this area,” Ian Howells, senior vice president-Honda Motor Europe, tells WardsAuto.

“However, it’s important to note that Honda’s U.K. plant in Swindon, plays an important role in our global manufacturing operations. We’ve recently invested over £200 million ($262 million) into the plant, as Swindon is developed into the global manufacturing hub for the new Civic 5-door model.

“Swindon will no longer be solely manufacturing cars for the European market, but will also export to North America. As such, our U.K. plant will be less reliant on the European market and will be feeding into Honda’s global operations. Honda remains committed to its manufacturing activity in the U.K.”

SMMT CEO Mike Hawes says: “The British public has chosen a new future out of Europe. Government must now maintain economic stability and secure a deal with the EU which safeguards U.K. automotive interests.

“This includes securing tariff-free access to European and other global markets, ensuring we can recruit talent from the EU and the rest of the world and making the U.K. the most competitive place in Europe for automotive investment.”

Daimler CEO Dieter Zetsche says of the U.K.: “Geographically, the country may be an island; politically and economically, it is not. It is now even more essential that Europe does not continue to drift further apart.”

And, assuming negotiations on a Transatlantic Trade & Investment Partnership deal between the EU and U.S. succeed, U.K. vehicle output could grow 7.3%, the SMMT projected before the Brexit vote.

But TTIP probably would not apply to the U.K. if it quits the EU, and it would need to negotiate a separate trade deal with America – something President Barack Obama says would not be a priority for Washington.

– with Andrew Burnyeat in Brighton, U.K.