I have not investigated in detail an under body mounting location for an air tank. But a small one gallon model like that sold by ARB should be quite easy to find a location for. I have done this on my other vehicle which is a Jeep. I like having a tank if only because it acts as a buffer in the system, reducing the amount of on-off cycling by the compressor. When I get around to installing a compressor in the Grenadier the first place I will investigate for the air tank is the location used for the urea tank in the diesel models.