It is quite possible to retrofit the later, DVD-based, Nav+ system
(RNS-E) to your car.  There is also an optional Bluetooth module which
can be connected and fully integrated with the Nav.  The amount of work
involved depends on exactly what HU was originally fitted to your car.

If it currently has a single DIN high HU it will be necessary to remove
the centre console and change some of the components to adapt it to a
double DIN height aperture - this will involve replacing, or modifying,
the air con control fascia.

Also, depending on what level of CAN bus implementation is on your car,
you may need to use a CAN bus simulator to provide some of the signal
required by the RNS-E.

Everything you need can be sourced from ebay.

There may be after-market options which provide what you're looking for,
and which would be easier to instal.  However, I believe that it is
worthwhile maintaining the factory-fit appearance of the car.