I just can't see it happening. I may be wrong, but I don't see them doing a mini cars land in that area - it makes no sense. You won't redo ToT, and last heard RnRC is not getting redone. Plus they don't have room for racers, and they just put in a Mater copy in TSL.
there is no space to do a cars land, especially not in that region. UNLESS they take the area for Fantasmic also, which could be I guess.Cars Land maybe the most cost effective land that they can create. They've spent more than expected on Star Wars, but need something to counter balance the park. They've already done a land in DCA. So it should be cheaper and easier for them to redo one rather than a whole new one.
Luigi's would be the 3rd attraction in this section rather than Mater's. Since like you said TSL has a Mater copy.
there is no space to do a cars land, especially not in that region. UNLESS they take the area for Fantasmic also, which could be I guess.