I already explained that the owner tried to create some interest in the company and used the "Brexit wave" to do it. Norton's problems began years before the referendum, like 2012.
Honda are also shutting plants as a result of changes to the car industry. Their own 'CEO' stated this. Nothing Brexit related.
"This is not a Brexit-related issue for us, it's being made on the global-related changes I've spoken about. We've always seen Brexit as something we'll get through, but these changes globally are something we will have to respond to. We deeply regret the impact it will have on the Swindon community." - Ian Howells, Vice-President Honda Europe.
Yes it is far too soon to speak about Nissan's future in Sunderland, but that still didn't stop you making it about brexit, when they made no public statement other than to say that they were halting the production of diesel cars. No mention about Brexit influencing the decision.