The Germans will have to make a choice between kissing ass with the UK, or a (probably uncontrollable) long-term devaluation of the Euro, or dumping the Euro and resuming the Deutschmark, orrrrr, a two-tiered currency system for the EU... *unless* they want their modern industrial economy to tank.
Germans will easily choose devaluation of Euro.
I have also a correction to make - German car export to the UK included Ford. Ford makes the cars it sells in the EU in Germany and that is why it got recorded as German cars in the statistics I used.