Based on seeing the successful German Army using armored cars to good affect, the United States Army decided to develop an armored car with a 37 mm gun and 6 x 6 drive. Four companies were asked to submit designs.
The radio used by the M8 was a SCR506, 508, 510, 608, or 610.
The M8 was made from all welded construction.
The floor had rather thin armor and many crews put sandbags on the floor to help protect themselves from mines.
In later models the steel gas tank was replaced by a rubber one.
Sand shields were mounted over the front and rear wheels, however, the rear ones were hinged and often removed to make it easier to mount tire chains. There was storage above the rear fenders and on the front hull between the headlights and racks for three mines on each side. The blackout lights were removable from their sockets.
The driver sat on the left and radio operator sat on the right and both had top and front hatches. The driver used a standard steering wheel.
The turret was located in the middle with the commander and loader.
Much of the crew's equipment had to be stored externally as there wasn't enough room on the inside.
The M8's turret had an open top.
All shutters and hatch covers can be closed and protectoscopes used for observation. There is a radio and speaking tube for inside of vehicle.
The 37 mm gun was rotated and elevated manually and was located in an open turret.
The fans in the rear blew towards the rear allowing for silent operation which allowed the M8 to approach the enemy stealthily.
A pintle was mounted in the rear of the M8 for towing a trailer.
There were 6 wheels that had mudguards, but these were often removed for battle. The wheels had an armored center and a bead lock to help prevent tires from collapsing in combat.