Sounds like you have one or more faulty ignition relays. These are the ones that power up the various circuits when you turn the ignition switch through the various positions. The faulty relay/s are likely intermittently switching while your driving and may need to be replaced or they may have faulty connections. Dealership or good auto electrician should be able to fix it up fairly quickly and cheaply. Guy I work with had similar problems on his Ford and it just ended up being one of these relays.
If it aint the above, maybe the ignition switch itself is faulty or has bad connections.
Otherwise........your car is haunted
:o
