If you are tech savvy at all its an easy fix.
that grinding noise is your blessing in disguise. it means the motor still works and the motor is the expensive piece.
to fix:
1. purchase a new antenna mast($20-$40)
2. Take off front passenger side wheel
3. Pull back the plastic in the wheel well(requires taking off some bolts and pins i believe)
4. unscrew the nut that the antenna comes out of(you know the one people can see)
5. Remove the motor from the wheel well
6. Remove the few bolts that hold the motor together
7. open up the motor(probably goopy as hell) and remove the white, probably broken, pieces of cord
8. put it all back together and in its place.
9. before putting the wheel well and wheel back on turn on the car/radio
10. after the motor stops whirring... put the end of the new antenna mast cord in the top of the motor(where that top nut was) and turn the radio off
11. it should grab the cord and pull it all back down into the motor
12. put everything back
sounds complicated but like i said if you know at all what you are doing its seriously no sweat.
Anyways, just tryin to help out. These things are huge money makers for dealers. The motor works perfectly fine...but the mast breaks. Owner brings it in saying its broken and the dealer says well...we'll have to replace the whole deal. rape i tell you...rape.
if anyone decides to do this and has questions feel free to pm me.