The Outside

Outside View, Small Below the collectors you can see the lifting platform, which helped a lot! Much better and faster than a fixed stand. Remember, the collectors are heavy, and a lifting platform can lift it up very easily!
Outside View, Small In this detail picture you can see the (isolated) pipes and the automatic air valves. The water enters the lower panels at the left, exits them at the right, enters the upper row at the right and leaves as - hopefully - hot water to the left. Notice how good the dimensions of the lower row are - it fits exactly horizontally!
Panel Closeup Panel Closeup Looking from the bathroom (window left of lower panel row).

A thing I could have made better

Given the fact that collector area is very cheap, I should have mounted the panels vertically directly on the wall. It would have saved me a lot of work with the mounting angles and a lot of expensive stainless steel screws, which in turn would have allowed me to add one more panel (the lower row maybe with 3 vertical ones?) without higher costs.

This would have looked a bit nicer, and the efficiency in november/december/january would have been better due to the larger area. In addition, the subventions given by the German state are higher for panels that are mounted vertically on the wall... And the panels would have had a better isolation from the back, and they themselves would have isolated the wall a bit more.

Disadvantage of that idea: in summer, the upper collectors would not have shaded the lower ones, but as the efficient area is much smaller... well who knows. Depends on the relation of diffuse to direct sunlight, which I do not know, and which is not constant. As a result I can not calculate the effects correctly.