I've looked at threads and apparently I am in minority about feeling this should be an essential in the Model 3 standard that I got in December.
I have a Subaru Outback that is really superb for me in Florida with the crazy drivers here in parking lots etc. in terms of warning. I just don't feel like the rear camera gives me a broad enough picture.
While I am at it, the other thing that bothers me is that the screen showing adjacent cars in other lanes shows too much forward of car and far too little in terms of those coming up behind me. I would have thought that others would have felt this could be fixed better.
I will say this- if I had researched it more, despite all the great features, I don't think I would buy the Tesla again with these features missing.
Please don't put me down too much. Just my opinion.
The research for rear cross traffic alert is too difficult for Tesla.
I think they didn't figure it out yet.