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: Ignition coil inspection
Primary Coil Winding 1. Remove the ignition coil. 2. Measure the resistance between the following lead holes using an ohmmeter. A and B, B and C - If not specified, replace the ignition coil. Specification 0.49-0.57 ohms [20°C {68°F}] Secondary Coil Winding 1. Remove the igni ...

Mazda 6 Service Manual: Removal/Installation
To remove the head restraint, pull it up while pressing the stop-catch. To install the head restraint, insert the legs into the holes while pressing the stop-catch. WARNING Always drive with the head restraints installed when seats are being used and make sure they are properly installed: Dri ...