availment of service tax credit

 I have the doubt related to the availment of service tax credit on the service or maintenanace of Motor Car.

Till date, i or we had taken the service tax credit on service tax paid for the service of Car (Qualis), which was used by our MD, and the same was purchased in the company name.Not only that, it is an asset to the company and charged depreciation every year at the time of finalisation of accounts every year.

but now, the central excise audit team object or not eligible the same on the ground that it is not related  to manufacture of final products.

So,please clarify the above matter with case laws if available.