Grossly overvalued? The main thing is, gross.

When it comes to the advantage that Germany has taken of the euro, Navarro is right about effect, if not motive.
The euro has been bad for German democracy and for German savers and may well ultimately prove to be a disaster for its taxpayers too, but it has been a boon for the country’s exporters. The euro is far weaker than the Deutsche Mark would have been (as was always likely to have been the case). This means that Germany’s decision to abandon its old currency in favor of the euro has acted as a disguised devaluation, a devaluation that has only deepened as the structural imbalances within the common currency have dragged the euro down still further.
Navarro sagte der “Financial Times”, Deutschland profitiere in seinen Handelsbeziehungen von einer “extrem unterbewerteten ‘impliziten Deutschen Mark'”.