What is the maximum allowed driving time during Multi-Manning (Mehrfahrerbetrieb / two drivers on board) within a 30-hour period?

1. Both drivers can drive for 48 hours without any rest
2. Multi-manning allows unlimited continuous driving for 7 consecutive days
3. Only the first driver is allowed to log driving hours
4. Within 30 hours of the end of a daily or weekly rest period, each driver must have taken a new daily rest period of at least 9 consecutive hours; maximum combined driving time is up to 18–20 hours