If I buy a new vehicle before getting divorced, is she entitled to half although we havnt been together in 6 months?

If you are not living together, money earned post separation is presumed to be separate property.  If you use your separate funds to purchase the vehicle, this does not give rise to a marital interest, unless you take affirmative steps to include his name on the title, etc.  Unless you pay cash for the vehicle, chances are there will be little or no equity in the car; hence, nothing to divide.  Lawyers.com offers general information and not legal advice.  Therefore you should confer with a family lawyer in your area to discuss this matter in greater details.  Best of luck~