A fastener clip includes a base plate and a first and second pair of laterally offset legs extending from the base plate. At least one first wing extends from the first pair of laterally offset legs. The at least one first wing has an engagement region. At least one second wing extending from the second pair of laterally offset legs. The at least one second wing has an engagement region, such that a distance between the engagement regions and the base plate is operative to vary continuously according to a slot thickness. The fastener clip is operative for insertion into the slot defined in a first engagement structure, such as a vehicle chassis.