We stayed in Wilhelmshaven for a near-by car show and as other reviewers mentioned, if you turn up outside 'normal' hours there's no-one on the desk and the hotel is locked up. After trying the hotel's number which wouldn't work for some reason on our UK phones, another German guest arrived and he kindly phoned the number and got the owner, and location of our key which was in a safe at the side of the building.
Once inside things went a lot better, the room was a good size and very clean, no air-con but large opening windows. Nice modern Ikea fittings, homely touches and everything was clean and in good order.
The area the hotel is in -and from what we saw, most of the town- is pretty run-down, it didn't feel particularly unsafe, but let's just say I don't think I'd want to turn up there on a dark winter's evening if I was a solo female traveller!
We didn't see the hotel's own car park, and just used the free on-street parking.
Breakfast was included in the price and was definitely the highlight of the stay- more food than you could hope for and beautifully presented- and you get to take what you can't finish with you. Staff in the morning were very friendly and chatty.