Mazda 6 Service Manual: No.19 excessive shift shock on torque converter clutch (tcc)

No.18 excessive shift shock is felt when upshifting and downshifting

No.20 noise occurs at idle when vehicle is stopped in all positions/ranges

Other materials:

Mazda 6 Service Manual: Immobilizer System
The immobilizer system allows the engine to start only with a key the system recognizes. If someone attempts to start the engine with an unrecognized key, the engine will not start, thereby helping to prevent vehicle theft. If you have a problem with the immobilizer system or the key, consult ...

Mazda 6 Service Manual: STEP 3: Contact Better Business Bureau (BBB)
Mazda North American Operations realizes that mutual agreement on some issues may not be possible. As a final step to ensure that your concerns are being fairly considered, Mazda North American Operations has agreed to participate in a dispute settlement program administered by the Better Busi ...