30 and a database 32 that holds vehicle navigation information maps road conditions and terrain lane information and changes touring instructions etc system 10 of the present invention minimizes the amount of airtime used between tcu 14 and server 16 to send a trip plan when a user asks the system for directions the vehicle 39 s local coordinates as determined by gps unit 24 are sent from tcu 14 to server 16 over network 18 the user also specifies their destination to the tcu entry of the user 39 s navigation instruction request including the destination information is preferably done vocally through the microphone but may be accomplished by other data entry means such as via user interface buttons the tcu transmits the vocalized destination to server 16 the server calculates the trip plan and generates a table of locations expressed as location coordinates such as gps coordinates and the corresponding navigation prompts e g turn left onto howel st these navigation prompts are preferably voice prompts but may include other forms of user notification such as textual messages or different audible visual or other signals the table with navigation prompts is sent to tcu 14 in vehicle 12 in an alternate embodiment the navigation prompts are sent as an audio file assuming voice prompts such as a wav file or an mp3 file in another embodiment the table includes locations identified in text form that are displayed or converted to audio by a text to speech tts component of processor 20 the navigation prompts could also include symbols that indicate common words such as u201c turn u201d u201c left u201d u201c onto u201d u201c street u201d and u201c avenue u201d.