[DrFeelGood]

It depends on your year. It could be center armrest power adapter and heated seats.

 

[DrFeelGood]

2006, Australia -- don't think we had the heated seats option... I believe this is the base model anyway... Thanks for your answer!

The later vehicles had a center console mounted stereo control. I believe that is the connector for the dock.
Mazda basically wires all they cars (of this vintage) with all the wiring for every option (equipped or otherwise).

My car did not come with power heated seats or Bose sound, however, I picked up the bits from the breaker and plugged them in and they worked.