According to Telematics Research Group (TRG), by 2011 28 million cars in the US and 73 million cars worldwide will be equipped with iPod integration solutions of one kind or another.

The researchers estimate that automotive auxiliary inputs will expand to about 60 million cars in the US and 150 million globally by 2011. Meanwhile, other technologies, such as Bluetooth A2DP, will emerge to support audio device integration in the years to come. TRG predicts Bluetooth A2DP audio interfaces will be installed in 8.5 million cars in the US and 25 million worldwide by 2011.

TRG founder and principal analyst said: "The rapid ramp up of available solutions from automotive OEMs is a stark contrast to the normal five-year product development cycle in the automotive industry. The variety of solutions reflects the swiftly changing landscape of the mobile audio market where branded audio solutions, surround sound and mobile device integration are driving market growth."

According to TRG data, 39 models from major auto brands currently sell vehicles into the US market with iPod adapters or auxiliary-input jacks.