Interior problem
1996 BMW 528 6 cyl Two Wheel Drive Automatic 130000 miles
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while driving, i hear a lot of noises coming from the doors, and from behind the backseats,
it seems like plastic noises,
you can hear it loudly especialy while driving over bumps and irregular surfaces.
how can i fix it?

try silicone spray lube, there are wet and dry types, use the dry type and spray the doors seals, hinges and lock assemblies generously. The seats too, don't be afraid.