If you are looking for the archetypal ambulance in Germany … my answer would be the Mercedes 123 in the “Hoch-Lang” version. Though this definitely depends on the timeframe. Some younger readers may, indeed, never have seen one of these “in the wild”. So, what are, or rather were, they?
The Mercedes W123 was, generally speaking, the range of “executive”-type cars manufactured by Mercedes-Benz between 1976 and 1985. With around 2.7 million cars sold before the before the more streamlined Mercedes-Benz W124 was introduced, it was ubiquitous in the late 1970s and well into the late 1980s. In Germany these cars were found as taxis everywhere, and in the emergency services mainly the ambulance services used them – as patient carriers as well as as other intervention vehicles. They were deemed indestructible, though this was bought at a higher price than, say, the off-the-shelf Volkswagen T3.
Much of the price tag was due to the basic vehicle. Which was already a conversion: Mercedes produced the W123 in a special long-wheelbase version of 3,425 mm for their 7 or 8 seater saloon cars. The same chassis was also available (as 240D, 300D and 250 models) as a “base unit” with a complete front body. This became the base for hearse and ambulance bodies, constructed (often using further standard body parts) by third party manufacturers. The best known of these were Binz and Miesen, with smaller companies like Hermann in Hamburg or the Dutch Visser works supplying further variety.
And here is a selection of them:
Please note that these images are scans from old 35mm slides in my archives, with resultant deterioration in colours and sharpness.