This hotel is easy to find and offers a bit parking lot behind the house. It's in the center of Sindelfingen, about 2km away from the fair. The rooms are clean and cosy. They don't offer breakfast but have a room with a kitchen and a microwave. A bakery is nearby.
The problem during my stay was that the owners (who run also a store on the other side of the street) where on holiday, so I arrived there, read the sign on the door ("Go to the store or call this number" and reached noone :/ . Luckily I was there with my car, so I could leave my baggage there and go to the stamp fair in the meantime. Seems that someone read my SMS and when I came back in the evening, someone (an employee of that store) really opened the door.
Due to that experience I give only 3 points.
Wifi isn't available but for only one night it didn't bother me.