My friends 99 sentra with 106k is making a strange noise underneath the right side of the car. It doesn't matter what speed or direction, its pretty random, comes and goes. I did notice today that when it was making the noise and I put in into nuetral, the niose stopped. My guess is something exhaust related. Im looking after the car for another 6 months while my friend is away and dont want to spend too much money fixing his cars problems.