Where is the power steering on a 2006 RX8?

The Power Steering on the RX-8 is electric, the rack itself is in the normal place, then there is a torque sensor where the steering column enters the rack and the ECU for it is located under the main car ECU.

There is a common fault where the coolant overflow dribbles over the connector to the rack and causes corrosion, this should be the first point of investigation if there is an issue.