Motorola is betting consumers will pay to have it both ways, gaining control over the content on their car radios and the flexibility of taking their music with them on their cell phones when they turn off their engines.

Motorola, the No. 2 maker of mobile telephones, is set to unveil a service called iRadio that will let users download preselected audio content from a range of providers on their home computers, dump it on their cell phones and listen to it on their car stereos.

The iRadio service, which will let customers download 10 hours of content at a time, will be available at the subscription cost of about $5 to $7 a month. When not driving, customers can listen to content on a phone with a headset.

Several companies are already betting on the potential, boosted by the popularity of a multitude of cell phones that enable music downloads.

Clear Channel Communications, the top U.S. radio operator, earlier this week said it plans to begin offering clips of programs over handsets by the end of 2005.