Spies Riding Shotgun
Slashdot has covered before the proliferation of black boxes - event data recorders - in modern automobiles, that automatically record data about what the car has been doing and make it available after the fact to police, insurance companies, and people suing you - just about everyone except you, in fact. We'll add to that with yet another story about the computerized spy riding shotgun in your new car.
This article quotes Erick Skrum of the National Motorists Association. It's a great political organization that fights multiple battles of interest to motorists, including black boxes.
Consider joining the NMA: http://www.motorists.org/
If your question is at all serious, there are products that you can use.
For instance, The CarChip.
My personal belief is vehement opposition to this kind of monitoring. Nevertheless, it is available. If she's driving a car you own, you can install it without any problem. If the car is hers, you might want to check with an attorney before installing any monitoring/spying equipment.
Jim