I’ve seen some pics where a newer model Cobalt platform works and can still be purchased through a dealer. Looks very close to the original and you get the small folding step off the back. Good luck finding a
an oem used one...been looking for that and an arch for years. I know custom stainless built the archs in 2000’s for Cobalt but keep reaching dead ends. Sure wish Cobalt would loosen up on that stuff....