The croozer manual states that to mount the axle hitch [with the hitch on the left/non-drive side and the quick release axle skewer oriented such that the quick release is on the right/drive side]:
The quick-release lever must be positioned on the right side of the bicycle (relative to the direction of travel). If the lever is on the left side, the quick-release skewer must be removed and reinserted from the right side
I'm not sure I want to put the QR on the cassette side though :/ . Does anyone know why they want the QR on the right here?