A non rhotic r in horse does not make a non rhotic r in sauce. That’s not a question of rhoticity because how you pronounce the r sound doesn’t matter…its that there’s an r sound at all in sauce.

There is no R sound in sauce.

You agreed with this in another comment regarding the British pronunciation of sauce sounding like ‘source’. That again has nothing to do with the rhoticity of the r in source, only that there is an r in sauce.

There is no R in sauce.

Yet here you refuse to come to the same conclusion that you did on another comment because 🤷

Been pretty consistent on this, dude.

I am not saying this is specific to you, I’m saying this is a difference in the pronunciation of the word. The issue here is the comparison to another word rather than someone just linking side by side pronunciations of the word in question: sauce.

There is no R sound in any of this. As someone else pointed out, it's an "aw" sound. Saws. Haws.