We're both in agreeance that the sedan and coupe will share a platform. You and I are essentially saying the same thing, that platform sharing makes the most sense.    Where we differ is I'm not entirely convinced we're gonna get a mustang sedan for this generation. The timeline just doesn't add up. The mustang is scheduled to get a redesign around 2029, we're likely not gonna see the sedan until at least 2028. They're pretty much guaranteed to share sheet metal apart from the rear doors and roof to keep costs down. So I see Ford holding off on the sedan until the next gen coupe releases. Rather than releasing an s650 based sedan for a year or two and then redesigning it to match the new mustang coupe generations looks. 

I have to confess that I am now more confused than I thought I was. But I found this which maybe helps clarify assuming this information is accurate:   CD6 Platform   And this quote was interesting:    

Don’t confuse platform code and product code, they are two different things.   The S650 will only last 6 years. But the D5 platform will be used again for the next gen.

I'll bet Tata will ship them over in knock down form and final assembly will be in a Stellantis plant. 

I don’t think anyone could argue with that. But then again, this is the Blue Oval forum. 😁

What do you mean? I'll I said is we've heard about getting a mustang sedan for several generations now, sn197, s550, s650, and it's yet to manifest. Likely because they're trying to find a way to use a platform that can underpin both the coupe and sedan while keeping engineering costs down. 

https://livetiming.net/ppihc/   https://ppihc.org/   HRG

You haven't been paying attention.

The plans have been all over the place. It feels like the last 10 years have been hearing about products, but not seeing anything manifest. The mustang sedan like you mentioned is something that's been right around the corner for 3 mustang generations now. I personally believe they're waiting to transition the coupe to cd6 or some other platform that'll make adding a sedan to easier to engineer. We know trying to use the s650 chassis to make a sedan would be a pain so they're probably not gonna do that.