I recently bought a used 2000 model mazda protégé/323 .it has done 130000 kms. I have a weird rumbling sound when I decelerate in 5th gear, on reaching 100km/h the rumbling sound starts and stops at around 80 km/h. this happens in all the gears i.e for 4th gear the rumbling starts at 80km/h and stops at 70 km/h. for 3rd it starts at 60km/h and stops at 50 km/h And so on. This rumbling sound is only there when the car is decelerated. i.e. when I push the accelerator pedal it goes off and when I let go the accelerator pedal the rumbling sound comes on at the above mentioned speeds. I found that the rubber bushing that is used for hanging the exhaust pipe from the car body is damaged, does this account for the rumbling sound. Or is it something else. Please advice.