As others have said, you cant afford it. Another reason why American and Canadian individual debt is out of control. This 'sense of entitlement' has to stop. Shame on your parents for encouraging this behaviour.
Sell your existing car and buy a good used Honda or something. Don't overburden yourself with financial responsibilities at this point in your life. Take the little money you make and have a good time.
BMW isn't going anywhere, it will be much more satisfying when you can safely afford one on your own.