The legal basis for the Industry, Commerce and Services (ICS) indicators is the Council Regulation N° 1165/98 of 19 May 1998 concerning short-term statistics STS-Regulation
Information on coverage, periodicity, timeliness and quality of data can be found in the Euroindicators metadata:
The definitions of short-term statistics variables are laid down in Commission Regulation N° 588/2001 of 26 March 2001 implementing Council Regulation N° 1165/98 of 19 May 1998 concerning short-term statistics as regards the definition of variables.
The classification by the main industrial groupings (MIGS) is laid down in Commission Regulation N° 586/2001 of 26 March 2001 on implementing Council Regulation N° 1165/98 of 19 May 1998 concerning short-term statistics as regards the definition of Main Industrial Groupings.
Information on new car registrations is not included in the Regulation .The information is obtained from the European Automobile Manufacturers Association (ACEA - Association de Constructeurs Européens d'Automobiles) http://www.acea.be.
The above legal references are published in the "Official Journal of the European Communities" (In order to receive these texts in one of the official languages of the EU of for more info, please contact Celex@opoce.cec.be or look for information on line http://circa.europa.eu/irc/dsis/bmethods/info/data/new/legaltexts.html).