Originally Posted by
ex-koelner
Why don't you stay in a hotel in Cologne for 3 nights and do day trips from there? Aachen, Bonn and Brühl are easily reachable by train or car. That seems a bit more convenient to me than changing the hotel.
+1
Also, this would enable you to leave your car in Cologne, get an NRW group ticket and take the train to Aachen, Bonn and Brühl which is (at least for Brühl and Aachen) quicker and cheaper than driving (and will allow you to avoid the usually crowded A4 motorway). Especially if you want to visit Aachen, the train (leaving at :15 and :43 every hour from Cologne Central Station) is definitely the better choice (unless you want to include the Dreiländereck in your visit which isn't really connected to public transportation) as every sightseeing spot there may well be reached by walking from the station.