As a sales person, can I deduct my new car which I use for visiting clients and conferences (business related) but also use for personal use.

[MonikaK1]

It depends. If you are self-employed, you can take either the standard mileage rate for your business miles, or you can take the business percentage of actual expenses and depreciation.

If you are an employee, your business expenses are not deductible on your Federal return under current law, but some states, including California, still allow employee business expenses if they exceed a percentage of your Adjusted Gross Income. 

Please see this TurboTax article and IRS Publication 463 for more information on deducting business use of vehicles.