I have 2018 chrysler 300s and I got the regular 8.4 uconnect with out nav but I want to upgrade to 8.4 with nav. I hear you can't and I would like to know why I can't upgrade. What is so different between a car with nav and with out nav. Is there a different mother board for the car or something that you are not allowed to do this.

 

I took delivery of my 2017 300s 2 days ago. The salesman and the parts manager told me it was possible. I'm not sure if our uconnect are different though.

 

If your dealer told you that, try calling another dealer and ask them.

It may be that they were trying to get you to go with the higher end system.
Another dealer may well tell you different, since they could make a sale out of it.

The big issue may be that fin on the top of the car. That is usually the GPS antenna, and if you do not have it, installing the factory GPS could be a problem.