The free Kempinski hotel for LH first class passengers at FRA -- which should be booked well before getting there -- also has a free shuttle bus from the hotel to the downtown area. However, often it is already booked or not running frequently enough to be of use. And the shuttle bus to the hotel from the airport isn't always that quick to pick up as it is a bit of a drive and then some between the airport and the hotel. And the shuttle bus from the hotel to the airport isn't all that frequent always during the day despite its being used by LH as an "airport" hotel -- although that may just be a way to try to convince day-room guests to check out on a schedule that the hotel itself wants for its own advantage.