You can get leather installed. It will not look exactly like the factory leather. Some after market leather looks great. Others look horrible. It would depend on where you got it done.

In general, you cannot get heated seats installed after, unless you wanted to replace the whole seat ($$$$$$$)

You cannot get the factory navigation installed. You will not be able to get any "in dash" navigation, unless you tried to replace the radio console.

There are many "on top of dash" navigation systems that are great. I recommend Garmin.