EODData is said to be good, and also cheap. http://www.eoddata.com/stockquote/INDEX/DAX.htm → Purchase End of Day Historical Data for this symbol from Nov 26, 1990
I had contact with their support desk. They are not offering daily historical OHLC data of the DAX future.
http://stooq.com/q/d/?s=fdx.f dax future back to 1998 free, click on download to csv at bottom of page. How are you going to account for rollover gaps?