A retainer for connecting two panels of a heat shield assembly, the retainer comprising: a central elongate panel having a length 1 and a width w, a top end, a bottom end and first and second long sides extending from the top end to the bottom end; a first side panel extending along the first long side of the central elongate panel and a second side panel extending along the second long side of the central elongate panel; and wherein the central elongate panel is corrugated, with corrugations running along the length of the central elongate panel from the top end to the bottom end.