A single piece, installation indicating clip to secure a foam part to a substrate is provided. The clip includes a pair of spaced apart and opposed curvilinear retention clip arms, a planar foam part retaining member, a bridge having first and second ends, and an installation indicator. The insulation part is captured between the planar foam part retaining member and the clip arms. The installation indicator includes a movable indicator pin. The pin is provided within a pin enclosure having a biasing member that urges the pin to its retracted position. A portion of the pin extends between the clip arms. Upon attachment of the retention clip to the fluid line, the indicator pin is pushed by the fluid line from its retracted position to its attachment indicating position, thereby visually verifying to the installer that successful installation of the retention clip has been made.