Method for manufacturing a fluid storage tank assembly for an off-road vehicle

In one embodiment, a method for manufacturing a fluid storage tank assembly for an off-road vehicle includes disposing a support ring (62) within a cavity of a rotational mold, in which the cavity is shaped to form a fill spout (52) of the fluid storage tank assembly. The method further includes flowing a liquid polymeric material (64) within the rotational mold such that the liquid polymeric material enters the cavity, directly contacts the support ring (62), and bonds to the support ring (62) as the liquid polymeric material (64) hardens.