I think you will only be able to control the volume of a zune not all iPod devices are supported either
Here is some information from the owners manual
and a link to the Lexus how to video for the audio system:
Lexus - Knowledge Center - How-To Videos - 2011 CT 200h
Compatible
iPod 5th generation Ver. 1.2.0 or higher
iPod nano
1st generation Ver. 1.3.0 or higher
2nd generation Ver. 1.1.2 or higher
3rd generation Ver. 1.0.0 or higher
iPod touch 1st generation Ver. 1.1.0 or higher
iPod classic 1st generation Ver. 1.0.0 or higher
iPhone will pair with bluetooth - upto 2 devices can be paired
iPod 4th generation and earlier models are not compatible with this system.
iPhone, iPod mini, iPod shuffle and iPod photo are not compatible with this system.
Items related to standards and limitations are as follows:
l Maximum number of lists in device: 9999
l Maximum number of songs in device: 65535
l Maximum number of songs per list: 65535
Other Devices Connected to USB Port
Operating portable audio devices connected to the audio system
The volume can be adjusted using the vehicle’s audio controls. All other adjustments must be made on the portable audio device itself.
When using a portable audio device connected to the power outlet
Noise may occur during playback. Use the power source of the portable audio
device.
Here is some information from the owners manual
and a link to the Lexus how to video for the audio system:
Lexus - Knowledge Center - How-To Videos - 2011 CT 200h
Compatible
iPod 5th generation Ver. 1.2.0 or higher
iPod nano
1st generation Ver. 1.3.0 or higher
2nd generation Ver. 1.1.2 or higher
3rd generation Ver. 1.0.0 or higher
iPod touch 1st generation Ver. 1.1.0 or higher
iPod classic 1st generation Ver. 1.0.0 or higher
iPhone will pair with bluetooth - upto 2 devices can be paired
iPod 4th generation and earlier models are not compatible with this system.
iPhone, iPod mini, iPod shuffle and iPod photo are not compatible with this system.
Items related to standards and limitations are as follows:
l Maximum number of lists in device: 9999
l Maximum number of songs in device: 65535
l Maximum number of songs per list: 65535
Other Devices Connected to USB Port
Operating portable audio devices connected to the audio system
The volume can be adjusted using the vehicle’s audio controls. All other adjustments must be made on the portable audio device itself.
When using a portable audio device connected to the power outlet
Noise may occur during playback. Use the power source of the portable audio
device.
