| I would advise you to save that 1200 on the NAV and leave the car as is. BMW sat nav systems are crazy and far behind industry standards......Honda accords have better NAVS.
Anyways as I said skip the in dash nav....and go for a handheld Garmin GPS system that you can instally in minutes in the car and use more easily that any car GPS system.
Advantages:
You can use it in any car.....if youre renting a car say in San Diego...just carry the NAV with you and you dont have to worry about printing maps finding yellow pages etc.
Easier Input availability
Easily updatable unlike car GPS especially the BMW DVD costs a bunch to upgrade
Anyways the final choice is yurs....but YEAH MUST HAVE A GPS....ITS A LIFESAVER AT ALL COSTS | 
