I was expecting mcfc1632 to tell us how little we know about negotiating but I think even he is stumped on this.
"The person setting the deadline is counting on the fact that it’s human nature to believe deadlines are real. It is in your best interest to be sceptical. If you decide that the deadline is real, determine where it comes from, whether an extension is possible, and what the consequences would be of missing the deadline." The trouble here is that the people setting the deadline (us) know the consequences could be dire (for us) but the other side (not just the EU but any other country we want a deal with) knows that too. They also know it may damage them but, in the long run, damage to the UK economy will lead to benefit for them (including those German car manufacturers). Now I realise that for some people this sounds like mental derangement, but to be fair I have always wondered about the sanity of some proponents of Brexit. Brexit can seem to be a sort of collective basket weaving.