There's an ISO connection for power, and the front speakers, but you need an adapter in order to hook up the rear amp as the pre-outs are on a non-standard mini ISO plug. You'll also need an antenna adapter in order to power the aerial, & a fascia surround to fill in the gaps.
Also bear in mind there is no ignition on feed to the stock HU (it uses CANBUS), so you'll either need to wire one in from the steering column or twin the perm live with the ignition on live and turn the HU on/off manually.