My key is lost forever n I can't afford new one. How can I start my car?

you can"t,100% can not start it.you can only get one at the dealer,BMW dealer. These keys contain a special microchip which is required for the engine to start. Without this chip, there is no way to start the car whatsoever, as this chip is what signals the immobilizer to allow the engine to start. Due to this system, these keys can only be purchased from a BMW dealer. You will need to show proof of ownership and proof of identity of the vehicle before the dealer will order you a new key. The cost will be around $200 for one new key,and that was 3 years ago. There is no way to cut a new key, or reprogram an old key.i would be looking real hard for your lost key.good luck.