"by duck!" what the duck are you thinking of? Who writes this stuff? when am I likely to use this expression? Or is traveling by duck a common means of transport in Germany these days? Maybe they deliver the post! Surely it would be better to have sensible phrases that are in common use in modern day Germany.
Yes that's funny, but the wrong word is not "Ente" = "duck" meaning the french vintage car 2CV, we really call it "Ente", The "via" part is wrong. "by" would translate as "mit" if you mean a vehicle. "via" would translate as "über" if you mean a stopover. Richtiges Deutsch: "Wir fahren mit der Ente" "We go by duck" "Wir fahren über Hannover nach Berlin". "We go to Berlin via Hanover".