OK, so I've been re-reading the navigation manual & it appears that the list of incidents is updated via RDS from FM radio stations & you can select them to avoid during route planning. However if you want 'live' traffic that can update & re-route your sat nav whilst you're driving a pre-planned route then you need the wifi connected.
I'm not sure this is correct.?
During the free trail I always had traffic, now its expired I have no traffic at all, its greyed out, as is the fuel and weather as expected.
(Phone still connects at random even after nearly two visits to the garage, one for two days. All garage did was re-pair the phone and it started to work again, but only for 5 days, now its randomly connecting again.)