Vehicle seat massage system comprising: a pump for providing pressurized air; an array of distributed inflatable air cells (22, 22', 22") equipped with an air conduit structure which has an access port connected to receive air flow from the pump and which has for each air cell of the array a flow connection for air flow to and from the air cell; a plurality of flow resistors (50, 82) arranged in the array of air cells such that the flow resistance to the air cells is increasing starting from the access port with increasing distance from the access port, and that height expansion of air cells due to inflation is propagating in a direction from the access port through the array and at last reaching a pneumatic end region of the array with a time delay; a valve arranged between the pump and the access port of the array, wherein the valve is configured to be switchable between an inflation state and a deflation state, wherein the valve is arranged to permit, in the inflation state, air flow from the pump to enter the access port of the array, and to permit, in the deflation state, air to flow from the air cells out of the access port of the array to be vented off; and means for controlling the valve to switch between inflation state and deflation state; characterized in that the means for controlling the valve include a pneumatic or mechanic feedback transmission connecting the pneumatic end region of the array with the valve, wherein the feedback transmission and the valve are arranged such that the valve is switched from the inflation state to the deflation state when the pressure at the pneumatic end region exceeds a threshold level. a pump for providing pressurized air; an array of distributed inflatable air cells (22, 22', 22") equipped with an air conduit structure which has an access port connected to receive air flow from the pump and which has for each air cell of the array a flow connection for air flow to and from the air cell; a plurality of flow resistors (50, 82) arranged in the array of air cells such that the flow resistance to the air cells is increasing starting from the access port with increasing distance from the access port, and that height expansion of air cells due to inflation is propagating in a direction from the access port through the array and at last reaching a pneumatic end region of the array with a time delay; a valve arranged between the pump and the access port of the array, wherein the valve is configured to be switchable between an inflation state and a deflation state, wherein the valve is arranged to permit, in the inflation state, air flow from the pump to enter the access port of the array, and to permit, in the deflation state, air to flow from the air cells out of the access port of the array to be vented off; and means for controlling the valve to switch between inflation state and deflation state; characterized in that the means for controlling the valve include a pneumatic or mechanic feedback transmission connecting the pneumatic end region of the array with the valve, wherein the feedback transmission and the valve are arranged such that the valve is switched from the inflation state to the deflation state when the pressure at the pneumatic end region exceeds a threshold level.