Kia Cerato 2019 Owner's Manual page 212

Audio system
Using a mobile phone or a two-
way radio
When a mobile phone is used inside
the vehicle, noise may be produced
from the audio system. This does not
mean that something is wrong with
the audio equipment. In such a case,
use the mobile phone at a place as
far as possible from the audio equip-
ment.
5 6
CAUTION
When using a communication
system such as a mobile phone
or a radio set inside the vehicle,
a separate external antenna
must be fitted. When a mobile
phone or a radio set is used
with an internal antenna alone,
it may interfere with the vehi-
cle's electrical system and
adversely affect safe operation
of the vehicle.
WARNING
Do not use a mobile phone
whilst driving. Stop at a safe
location to use a mobile phone.