It’s used by UK emergency services, I believe Audi have it as standard in all their new cars too. It’s very handy for those who like to wander a little off the beaten track shall we say.
Are you sure that GPS is actually enabled on your phone? It will be disabled on most phones if you've selected the battery-saving mode (or otherwise disabled it).
If GPS is turned off your phone will be trying to triangulate your vehicle's location from nearby phone masts (rather than using satellite data), which would explain the poor accuracy and lack of responsiveness.
I'm so far behind with time I've got no idea what you lot are on about. I had little to do today, So had a stroll round the streets collecting pop bottles so as to receive the deposit back, I turned up at the shop with a big haul, and excited, only to be told by the owner, to get a life and *** off.
Without knowing the make and model of the phone (so that I can consult the manual) that's not an easy question to answer!
Start by checking that both 'Data' (or 'Data Connection') and, importantly, 'Location' are enabled. Then look to see if there are any power-saving options on your phone and make sure that you disable anything like 'battery saving'.