Stand alone option.

It's on my tag and sheet. IIRC, its up with the M codes 2 line from top. Like where they are in the green stripe 71 being discussed now.

I have other examples on tags too. Don't have access to those pics right now though. The cars that have then typically have other molding options, like A46, but that is just coincidence. They tend to be cars optioned up some.

I have tag info on two A78 cars with M28. And the loaded Juliano sunroof car has M28. My car has it and it's not an A78 either. All 4 of those are A46 though. That's just 4 cars off the top of my head.