Germany - Wolfsburg and Hamburg

I did a week's trip early in May to Hamburg from London by train, stopping off for two nights in Wolfsburg so I could visit the VW museums there.
First off both my long trips from London to Wolfsburg and then Hamburg to London were severely disrupted by DB screwups. Not worth writing out all the infuriating details but I'm seriously considering in future going to Koeln and spending the night there no matter what.
I stayed at the Premier Inn in Wolfsburg which turned out to be further away from the station than I assumed from Google Maps. Both routes were also not very safe-feeling at night, as one was past the back of a shopping centre and the other involved very secluded footpaths underneath and around a large road junction.
Having visited Dresden before, the architecture and town-planning of central Wolfsburg reminded me a lot of the area of Dresden between the touristy bit and the Hbf, suggesting that in the 1950s and 60s capitalist company towns and communist ones were more similar than one might expect. The specialist charitable VW museum was very interesting with some odd "Beetle" derivatives and customs on display. The museum within the Autostadt was a bit expensive for the the size, which was smaller than implied on the website. I've now been to the "official" marque museums for Daimler-Benz, Porsche, BMW and VW, and the Daimler-Benz one in Stuttgart is by far the best.
I liked Hamburg, there's very little historic about the city centre but some fun attractions. A major warning I would give is about Miniatur-Wonderland. Based on previous experience with tourist attractions I expected to get a ticket online on Friday for either Saturday or Sunday, but Saturday was totally sold out and I only managed to get a ticket on Sunday by booking an expensive "VR experience" in addition. I would recommend booking at least two weeks in advance. However, it definitely is very much worth seeing.
The Kunsthalle was good, the most famous painting being Friedrich's "Wanderer Above the Sea of Fog". I did have a bit of a "Mona Lisa" surprise feeling that it isn't actually very large, with the images everybody's familiar with making you expect it to take up a whole wall. It wasn't mobbed and in fact wasn't even specially marked on the museum's floorplan. More generally there are some interesting German Impressionist paintings from artists less internationally known than the French Impressionists. The Kunst und Gewerbe Museum was also very good for 20th century items, although a bit messily arranged with some back-and-forth to see everything.
I stayed at the Ibis Alsterring in the inner eastern suburbs, which isn't actually very close to the Alster lakes but has very good transit links with separate S-Bahn and U-Bahn stations within walking distance. The exterior and corridors of the hotel were a bit "1970s youth hostel" but the rooms were much more comfortable. There were some good cheap ethnic restaurants in the area - over my five evenings I had Vietnamese, Persian, pizza and hamburger.