Mazda 6 Service Manual: No.20 noise occurs at idle when vehicle is stopped in all positions/ranges

No.19 excessive shift shock on torque converter clutch (tcc)

No.21 noise occurs at idle when vehicle is stopped in d, s, l ranges, or in r position

Other materials:

Mazda 6 Service Manual: Radar Sensors (Rear) (Some models)
Your vehicle is equipped with radar sensors (rear). The following systems also use the radar sensors (rear). Blind Spot Monitoring system (BSM) Rear Cross Traffic Alert (RCTA) The radar sensors (rear) function by detecting the radio waves reflected off a vehicle approaching from the rea ...

Mazda 6 Service Manual: Drive shaft (atx) disassembly/assembly
1. Disassemble in the order indicated in the table. 2. Assemble in the reverse order of disassembly. Boot Band (Wheel Side) Disassembly Note Note The boot band does not need to be removed unless it is being replaced. Remove the boot clamp with end clamp pliers as shown and discard the cla ...