Tomtom Navigator 3 and XDA Advice

Hi, I wonder if any one could give me some advice re Tomtom Navigator 3 Kit and the XDA2
I am confused as to what exactly I need to buy.
I already have the XDA2, I think I need TTN3 kit, an SD Memory Card, and a car kit.
Is that correct or are there any other items that aren't included in the kit that I will need?
Also, will I loose any of the telephone functionality when when using the navigator?
Any help, advice or tips would be greatly appreciated.

[Charlie]

Welcome to our forums.
That should be all you need. Will you be getting a wired or wireless system?