Automotive components do fall under the provisions of Legal Meterology Act, 2010 (earlier it was known as Standards of Weight and Measurs Act,) .It means on the packing full details about manufacturer and marketed by, Tel No. e-mail id, Expiry etc. is required to be provided. Further, Automotive components do fall under the Section 4A's Valuation Rules. If your supplier (say manufacturer ) had manufactured and packed these components for the purpose of selling it to you by affixing the MRP then certaintly he would pay the C.E. Duty on the basis of MRP Valuation.
Further, if you repack it in your own packing for the purpose of selling it to ultimate customer by enhancing the MRP then you would have to pay the excise duty on the enhanced value of such goods.
Kindly also refer the Rule 5 of the CENTRAL EXCISE (DETERMINATION OF RETAIL SALE PRICE OF EXCISABLE GOODS) RULES, 2008 [Notification No. 13/2008-C.E. (N.T.), dated 01-03-2008].
Rule 5 for your kind perusal:-
Where a manufacturer alters or tampers the retail sale price declared on the package of goods after their removal from the place of manufacture, resulting into increase in the retail sale price, then such increased retail sale price shall be taken as the retail sale price of all goods removed during a period of one month before and after the date of removal of such goods:
Provided that where the manufacturer alters or tampers the declared retail sale price resulting into more than one retail sale price available on such goods, then, the highest of such retail sale price shall be taken as the retail sale price of all such goods.