the asset must be entered under the business entity that bought it - you'll come to a page with a link for assets and depreciation (this is for non-vehicles) and another link for cars, trucks, and other vehicle expenses. choose the appropriate one and the program will take you through the steps to take 179
note that there are 4 versions of online. you'll need premier or self-employed to do a schedule c or rental real estate. Note that only the desktop - TurboTax Business (window only - 64-bit operating system) does business returns - S-corp (1120s), C-corp (1120), partnership (1065). trust or estate (1041)