This unit plays audio files as follows:

CAUTION
Do not use an audio file extension on files other than audio files. In addition, do not change the audio file extension. Otherwise, the unit will not recognize the file correctly resulting in noise or a malfunction.
NOTE
MP3/WMA/AAC/OGG files written under specifications other than the indicated specification may not play normally or files/folder names may not display correctly.
Operating Tips for OGG
Audio SetMazda 6 Owners Manual: No.7 abs warning light stays on more than 4 seconds with ignition switch on
Diagnostic procedure
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there is a
problem, check to make sure conne ...
Mazda 6 Owners Manual: Oil pressure switch removal/installation
Warning
When the transaxle and ATF are hot, they can badly burn. Turn off
the engine and wait untill they are cool before replacing ATF.
1. Disconnect the negative battery cable.
2. Remove the under cover.
3. Disconnect the cord assembly connector.
4. Remove the oil pressure switch.
...