The main production variant, the M3A1 scout car, was a lightly armored, open topped, machine gun armed, four wheel drive vehicle designed to be used in the reconnaissance role.

[1][2][3][4] The armored body of the M3A1 Scout Car was produced by the Diebold Lock and Safe Company, it had a maximum armor thickness of 0.5 in (13 mm) and was open topped, providing good fields of view but no overhead protection for the occupants, a canvas cover was provided for protection from the elements.

Tested in 1934, the M1 Scout Car was an improvised, open topped four-wheel drive vehicle based on a commercial White ½-ton truck design.

The M2 Scout Car weighed 3.95 short tons (3.58 t), was powered by a 94 hp (70 kW) engine and retained the top speed of 50 mph (80 km/h).

Primary external differences from the M3 were a widening of the body over the fenders, the removal of the rear door of the M3 and the addition of the front roller.

It was the only version to see service outside of the United States, with the exception of Philippine Scouts in the 26th Cavalry Regiment (PS) who were issued the M2 variant before 1937.

[1][2][7][6][14] The M3A1E1 Scout Car was developed to increase the range and fuel economy of the vehicle, it was powered by an 81 hp (60 kW) Buda-Lanova 6DT-317 six-cylinder diesel engine.

[citation needed] The M3A1E3 Scout Car was an experimental version fitted with a pedestal mounted 37 mm Gun M3.

[2][19] General George Patton used an M3A1 as a command vehicle, modified with additional armor and a raised fighting compartment.

[20][21][22] In British Commonwealth service, the White Scout Car was regarded more as an armored truck, reflected in the designation "Truck, 15cwt, 4x4, Armoured Personnel", and was used in a variety of secondary roles, being issued to engineer, artillery (as an observation vehicle for field artillery observers) medical (as a protected ambulance) and signals units; within the Royal Armoured Corps’ Tank and Armoured Car Regiments it usually served in Squadron or Regimental headquarters.

[citation needed] After the war, many vehicles were sold, mostly to Asian and Latin American countries while they remained in Soviet service until 1947.