That's odd, I always thought it was the bootspoiler that made the difference. I have around 10+ E46's in my collection, most of them Autoart. I have 4 Kyosho's, being both the grey CS and blue CS, M3 cabriolet and M3 cabriolet with CSL wheels. Both cabriolets don't have the boot spoiler though, the Autoart coupes do have them. All the CSL's don't have separate spoilers but they're kind of integrated into the trunk.
However, both the CS cars have a grey/dark interior, whilst the silver regular E46 coupe from Kyosho has the laguna seca blue details in it. I once had that regular M3 with the blue interior with CSL wheels, they were probably swapped. Sold it later when I bought the CS version.
I should really make some pictures one day too 😄