BMW 740 IL 2000 Navigation System Problem -please help-

I bought a new 2000 740il and the navigation system went black recently and the radio shuts off after 2 min. and you have to double click the on\off to get the radio back on, then it shuts off again after 2 min. The navigation screen and system does not work and I did not disconnect the battery, lose power or get a jump, as many first ask.

The dealer has no solution but to sell me a new car or a new system. I am frustrated and feel that at the price I paid for this vehicle, there should be a reasonable solution for an expensive computer system and feature that dies after just 5 years. Dealer wants over $2,600 for replacement or fix.

Please help

Thank you.

were u ever able to get this resolved and if so how. My car recently did the same thing