im not as senior here, but i suffered teh same problem in my cuore. i can tell u what i did and it helped reduce the problem by half.
Cuore, by default is a very noisy car. especially its dashboard raises hell.
you can do teh following things.
1) grease the joints of the glove cpompartment, the door hinges and tighten the screws beneth the front seats. (you wont believe how much noise these bastards make. and they become loose after every 1000 km or so)
2) if you hear a certain mettalic noise on bumps, the culprit is teh cng cylinder holder. open your cars boot, and lift the tray(where speakers are kept). on th eleft side, you will see a black frame made out of thick stel wire which secures the area around teh nozzle of cylinder.this frame is a bit flexible. during a bumpy ride, this noisy lil idiot clangs on the plastic on teh interior making a CLING kinda noise which is very irritating. slightly lift it, and put some tissues in between this metal frame and teh interior. i did this 1 year ago and it never gave me a problem again.
3) also, try not to keep anything loose in teh boot or on the floor.
4) the dashboard noiise can be reduced by tiightening the 2 screws on top of your speed o meter.
hope these tips help...