I have an older system, so this may not work, but unless you get a better answer, it's worth a try.
Initiate the voice system, then say "Save Name" and follow the prompts. (say the name, repeat, then dictate the number). When you're done with dictating the number, say "Save". It will not let you save names that are phonetically similar.
To dial by name, initiate the system, then say "Name" and follow prompts.
To review stored names, initiate the system, then say "Read Phonebook". You can say "Dial" after any name to call that name.
The voice system memory is entirely separate from your phone's memory, or the copy of it in the car.
Edit: I guess I should re-load threads before answering after I get interrupted. 