Gruppe Sechs (or Gruppe 6) is a security company featured in Grand Theft Auto III, Grand Theft Auto: Vice City, Grand Theft Auto: Liberty City Stories, Grand Theft Auto: Vice City Stories, and Grand Theft Auto IV. The company uses Securicar vans to transport goods or money.
The "Gruppe Sechs" name is a German language pun on the well known infamous European security company Group 4. However, this can be pronounced as "Group Sex", which is obviously how Rockstar Games intended it to sound, giving them a double pun foron the name. In GTA IV, the name is shortened to "Gruppe 6" but the Securicar still features "Gruppe Sechs" in much smaller print on various surfaces.