While the character of Josef Matula is mainly linked to Alfa Romeo cars, the lawyers are mainly Mercedes-Benz drivers. Dr. Dieter Renz used to drive a W114 and a W126 model. Dr. Johannes Voss drove a C208 CLK model. Dr. Markus Lessing always had sedans of the C-Class (W203 and W204 models, always in black). The exceptions are represented by Dr. Rainer Franck, who was a BMW 7 series driver (owned two E32 and one E38 model) and by two Opel Senator A used by Dr. Renz between the two Mercedes.
Claus Theo Gärtner plays in most episodes of the series.
Josef Matula (Claus Theo Gärtner) always drives Alfa Romeo sedans painted in metallic silver, except for three seasons (6, 7 and 8) where he drives a 1985 Audi 90 B2 followed by a 1987 Audi 80 quattro B3 (both in white). The characters' first car was a 1976 Alfa Romeo Giulia Nuova Super (white), which was Gärtner's private car. For a couple of episodes in season 4, after a roll-over during a chase scene, this was replaced by a silver 1984 Alfa Romeo Giulietta. The two white Audis were followed by a 1987 Alfa Romeo 75 T. Spark, starting from episode 8.05, where lawyer Dr. Rainer Franck (Rainer Hunold) makes his debut replacing Dr. Dieter Renz (Gunther Strack). In season 9 followed a facelifted 1988 model of the 75 T. Spark, probably replaced by an identical one in season 10. In season 13 it was the turn of a then brand new 1992 Alfa Romeo 155 V6 (in the first episodes there was a brown car, followed by a grey one), replaced by a facelifted model in season 16. In season 19 Matula switched to an Alfa Romeo 156 2.5 V6, replaced by a facelifted model in season 22 and then again with a 2004 2.0 JTS model in season 24. Since season 26 he began driving Alfa Romeo 159 model, a 2.2 JTS followed by a 2.4 JTDm TI (first diesel car of the character). in one later episode Matula is shown working with an oldtimer Alfa Romeo he owns. In real-life actor Claus Theo Gärtner is a car lover and appassionate racing driver, and an Alfa Romeo enthusiast and driver. Most of the car stunts on set were made by himself.
The lawyers of the show are always fine men characterized by a particular hobby. Dr. Dieter Renz loves literarure and art. Dr. Rainer Franck shares a passion for cars and bikes with Matula (indeed, they first meet at a motocross event). Dr. Johannes Voss is a boxer, while Dr. Markus Lessing is a saxophone player.
Neither Matula nor the lawyers are married, but they do have several affairs during the series. Dr. Renz and Dr. Lessing were married in the past, the former being divorced and the latter a widower. Only Dr. Lessing has got a daughter. Both Dr. Renz and Dr. Franck leave their roles to follow a relationship, which is supposed to become a marriage.