I always wondered about that. My guess is that the big cost for the factory would be the dash harness. Tooling for everything else already existed - stamping for the dash frame, injection mold for the cluster. Likely a low percentage of total A body production got the Rallye dash, not enough demand to keep the option maybe?
This is too bad. Does anyone know if full on reproductions of the ralley dash are available? I know the outer skins are from pg, but does anyone sell the entire assembly?