I have a 2015 Q60S non-nav, if i swap to a 2011 nav do I need to change the faceplate as well or can I reuse the one I have?

 

Are you talking about the radio/HVAC switch assembly (with the clock)? If so, yes, you will have to swap out for a NAV-compatible assembly. NAV and non-NAV switches are not interchangeable. The wiring connectors are the same but the functions are not.

You should be able to swap over your original trim from your switch assembly to the NAV one- it is just a few screws, but I am not 100% certain about that aspect.