If I understand your question correctly, yes you can play your iPod and TomTom at the same time. Any iPod with 3G standards the most recent operating system will also perform this task. I am also an iPhone 4/32 and Jobs and the gang thought of everything. The option is on TomTom’s screen. I unfortunately am not very good at do all four or five things at the same time, focus on the route, listen to music, and look on the screen and pay attention to TomTom at the same time, God forbid if I must touch something. My wife refused to ride with me when I pulled out that Garmin’s. So I learn to plan my route before taking off. I do a screen snap of the map than print it with WePrint Server and clamp it to my windshield. It is always in the last10 to 5 miles of my destination that I need TomTom.
VisualMap is another good app when planning a group ride or just keeping a record of places and trips. You can point at a places of interest or restaurants, and take a picture of the location, with the map pinned to the destination using screen shot of those final 10 miles.
I notice that there is another app NAVIGON for $80. The price will drop and there is very little difference between the two apps.
I subscribe to TomTom Traffic. It is a good resource in real-time of road problems and ways to get around them. This option a great option for any vehicle.