Yea and the DAB radio uses your phone, think a unlimited internet boosters needed :/
O2 told me if i go over my internet allowance they dont charge me any extra, they just slow it right down to snail speed
Not sure about the sat nav but Streaming live radio via the internet will contribute to your data allowance.
As a rough estimate, streaming music at 128Kbps for an hour uses around 56MB (Megabytes) of data.
128Kbps (kilobits per second) is towards the higher streaming rate on an internet radio – stations like BBC radio 4 stream to internet radios at the much lower rate of 48Kbps.
(copyed off Which.co.uk) hope that helps x
If you're using DAB radio on Intellilink, that does not use phone data, it's not connected through your phone at all. However, when you're using Intellilink App "TuneIn Radio" to listen to internet radio through the App that will use data on your phone..
With regards to BringGo. Once you have in App purchase of Western/Eastern European Map, maps are actually on your phone and so it does not use Data for mapping information. However, it does use small data to update traffic information on your route.