Why do you state that only 30% of the car expenses is deductible?
If the vehicle is used 30% for business than only 30% of the actual expenses will be deducted.
Business miles will be deductible in full at the standard mileage rate. Either mileage or actual expenses are deductible. You cannot deduct both.
Let me know if you have any question.
Please note: This advice is provided with the understanding that all the relevant facts have been provided by you. Any change in facts might affect the advice given and hence may not be relied on in such cases. Nothing contained in this reply was intended or written to be used, can be used by any taxpayer, or may be relied upon or used by any taxpayer for the purposes of avoiding penalties that may be imposed on the taxpayer under the Internal Revenue Code of 1986, as amended.