Perhaps SGM will kill me for this one coming too late, he was in Berlin recently. But then, he had refused my tips, so I might survive.
Glynsky on the other hand has not been to Berlin and the following might be a reason for him to go. And for you as well.
Glynsky is into classic cars and racing, so this is a must see in Berlin:
The former tram depot from 1900 hosts dozens of repair shops for and dealers in classic cars. There are shops for parts and accessories, a restaurant, classic car clubs, Scuderia Berlin (Ferrari and Maserati), etc.
Yes, Glynsky, there are Alfa Romeo experts too.
The last time I was there, approximately 250-300 classic cars were on display and/or for sale.
In addition, people can rent glass boxes to park their car there. For them the cars are safe and for you on display. Like a 1937 Maybach, a Jaguar convertible from the 40s with hardtop, Rolls Royce, Bentleys, Mercedes, Aston Martins, MGs, Ferraris, Maseratis, BMWs and one of my favorites:
a Marcos GT.