It was a serious problem that we don’t have a car to bring Do-Do with us, but now it has been solved. We have bought a child trailer (Kinderanhänger) at ebay.de for only €50 (€30 for the trailer + €20 for transportation), which is much cheaper than those in the bicycle shop (over €600). We brought Do-Do to Rohensee, Festspielhaus and Superplus, and he looked enjoying.