Radio
The external environment (hill, building, tunnel, car park, underground car park...) may disrupt reception, including in RDS tracking mode. This is a normal phenomenon of radio wave propagation and in no way indicates a fault with the radio.
SELECTING A STATION
1.
Press the RADIO key to display the list of locally received stations, sorted alphabetically. Select the desired station by turning the ring and press to confirm.

When listening to the radio, press the
and
keys to automatically search for the next lower and next higher frequency.

When the “RADIO” screen is displayed, turn the ring or use the 4-way selector to select the previous or next station in the list.

Press one of the numeric keypad keys for more than 2 seconds to store the station being listened to. A beep confirms the storage.
Press the numeric keypad key to recall the stored radio station.
RDS - REGIONAL MODE
1. 

2. The shortcut menu for the radio source appears and provides access to the following shortcuts:

!
Select the desired function and press OK to confirm and access the corresponding settings.

! RDS, when displayed, allows you to keep listening to the same station through frequency tracking. However, under certain conditions, tracking of this RDS station is not guaranteed across the whole country, as radio stations do not cover 100% of the territory. This explains the loss of station reception during a journey.
Test yourself
A quick Citroen C5 Aircross quiz: every answer comes with an explanation and a link to the manual page.