the job of a compass is always to point true north not to point the direction your driving, the compass will always keep your maps pointing correct way they will rotate round as you move so north on map will be true north. heres video to give you idea how maps self correct to north using compass http://www.youtube.com/watch?v=yR_lDvV2ks4
remember map view is different for navigation so you always be rotated to way your driving