Maserati A6 (1947–1956) were various cars made by Maserati of Italy, named for Alfieri Maserati (one of the Maserati brothers, founders of Maserati) and for the straight-six engine.
The 1.5-litre straight-six was named A6 TR (Testa Riportata), and was based on the pre-war Maserati 6CM; 65 bhp (48 kW). It first appeared in the A6 Sport or Tipo 6CS/46, a barchetta prototype, developed by Ernesto Maserati and Alberto Massimino. This became the A6 1500 Pininfarina-designed two-door berlinetta, first shown at the 1947 Salon International de l'Auto in Geneva (59 made) and the spider shown at the 1948 Salone dell'automobile di Torino (2 made).
Source: Wikipedia (original)