Hi Roy the mp3 version will work the same as your unit now, however as i mentioned in andromeda 411 reply about his display unit, as far as i'm aware you'll have to get the new radio tech 2'd to work with your head unit, apparently they are all programmed together at the factory, so your display will only work with your head unit and vice versa.
this is just from what i've read else where, havn't done this myself yet!!!
i want to try and get the trip computer working, but will need a different display unit first.
hope this helps.