Post by
K03sport »
https://forums.nicoclub.com/k03sport-u129071.html
Wed May 13, 2009 1:21 pm
Swaybar bushings.
Since it happens on bumps, think of all of the things that move when you go over a bump. If you can, try to isolate one side of the car and only roll over a bump (speed bump) in a parking lot and see if the noise reproduces itself.
If you have any dynamat or equivalent sound deadening material handy, apply some (3-4"x1") to the heat shield either in the corners or centered along the longest side. The deadener should eliminate the sound if it is that heat shield.
Other possibilites could be exhaust hangers.