When a customer is upgrading to the RHR, and the vehicle is 2007-2011, it's very likely the factory radio is an RER (as the RER's are older tech and are prone to issues due to age). The RER has 3 antenna ports, so the vehicle will have 3 antennas in the dash (White - AM/FM, Blue - GPS, Curry - XM). In 2012 when the RHR debuted, FCA combined GPS and XM and used Curry moving forward, until the Uconnect 5, where it changed to Blue.
The RHR is compatible, but will require the multiplexer U-GPSMPLX to combine the blue and curry in the dash to plug to the curry on the RHR radio.
RER
RHR
