Not overnight here (is possible) but used the service station because of the weather. stay overnight in Lübeck where nothing is available. Right on the highway. Paid 20 cents (vending machine) for emptying the cassette toilet and 20 cents paid for 18 liters of (shower) water. Ideally these kinds of points, there should be a lot more of them. For the CP in Lübeck also definitely recommended, although it should cost a euro. Ideal if you have to discharge / replenish.