What type of car this is?

Sorry, Jaap, but you are utterly wrong with your assessment. The Type D5 in the book on Stoewer motorcars mentioned by you, features the typically rounded and slightly slanted radiator which this manufacturer used. It has hardly anything in common with the Benz-like radiator on the car in the photo. What's more, the manufacturer's logo is entirely different.

No, we can absolutely rule out a Stoewer. They used a completely different radiator in the early 1920s and also their logo looked entirely different. See my comprehensive Stoewer gallery showing lots of original cars from that era, in particular D-Types of all sizes: https://vorkriegs-klassiker-rundschau.blog/bildergalerie-nach-marken-3/stoewer/

Do you have reference pictures? I can’t find any where the radiator is convincingly the same, Stoewer seems to have more a round radiator, i can’t clearly see it but behind the right headlighr seems to be a sharp ‘fold’ in the radiator mantle.

Benz 27/70 seems to match well in this picture specifically:
http://tikobv.nl/images/MB/clip_image111.jpg

Although i’m not convinced on radiator shape, but it might be a little distorted in the photo. The benz radiator looks more straight up instead of slanted back. But then again, the headlights look slanted back as well which should not be correct.

The radiator looks slightly slanted simply due to the angle from which the photo of the original print was taken. That's why I advocate a proper scan of the print which should enable us to take a closer look at the radiator badge.

Thank you, you seem to be on a good track. The biggest difference I see in most type P Brennabors I can find is that this car has 12 spoke front wheels. Do you know if these cars used those as well?

It's amassing how little is known about Brennabor and how so few car remain of the once largest car producer in Germany.
I don't know about the 12 spoke wheels, but the pictured car definitely has a "B" on the hubcap.
I may be wrong, but I believe the only model with the V radiator was the Typ P.
According to the link below de.wikipedia, the external gear shift lever was moved to the interior of the car after 1925.
https://de.wikipedia.org/wiki/Brennabor_Typ_P
https://vorkriegs-klassiker-rundschau.blog/brennabor-once-the-largest-german-car-producer/

I am not sure that this car is a Brennabor P Type. Indeed, early examples had a v-shaped radiator mask, but the hubcaps and wheel studs looked different. Moreover, all Brennabor P types on the photos from my collection feature just ten instead of twelve wheel spokes (see my Brennabor gallery: https://vorkriegs-klassiker-rundschau.blog/bildergalerie-nach-marken-3/brennabor). Last but not least, the badge on the radiator doesn't look right (should be a single letter "B"). Probably it was a larger car from a more obsure German manufacturer, like Beckmann, for example. A proper scan of the original photo would certainly help identifying it.

Thank you Michael, I do see the radiator shape, outer gear lever and the bent front axle as good signs it might be a Brennabor, although you see similarities in many German brands even Benz.
I got this picture from the grandson of the person laying on the right fender, lets see if I can obtain a better quality photo.

Neither the shape of the radiator, nor the position of the gear lever or the number of the wheel spokes is Brennabor-specific. Many German marques used a Benz-like radiator in the early 1920s and you could even buy ones as aftermarket pieces for pre-WW1 cars with flat radiator. I've got dozens of photos in my collection showing unidentified carswith similar features. The only way to find out the manufacturer of this car is obtaining a high resolution scan of the radiator badge.