So made a vector image of Konqi driving a trabant. Mostly because all land marks are sort of... well boring, and the ampelmann illustrations too touristy (according to the Germans)
The idea being that the Trabant is the best suggestion for a Berlin symbol and its old, has a K logo and Konqi driving. So my suggestion is to scrap text entirely on it and just make the car pretty big,.
The upside is that its a totally cleaned out, two colour vector image, meaning it can be printed in a huge huge size and it has no fiddly bits, no large amounts of colour either...