We will be renting a car from Munich for one week, traveling to (and through) the Black Forest, and then dropping it off in Frankfurt. One debate is whether to initiate the rental from Munich airport vs train station downtown (we will staying near the Marienplatz). I'm thinking it would be easier to take the S-bahn to the airport and rent the car there, thus avoiding driving our rental through the main city.
But here's the situation when we drop the car off in Frankfurt: we need to catch a train to northern Germany. If we drop off at the airport, the scheduled train trip is about an hour longer than if we were to drop off the car at the main train station and take a train from there to our destination. Is the main train station easy to get to or would the extra driving through town not be worth any time we save on the actual train ride. Frankfurt Airport is outside the city and (in my opinion) easier to get to. But maybe not....