my 1996 quattro dies
 

hi all im a newbie,,a bought an a4 2.6 quattro last week,drives great,but on my way home it just died without warning,the battery light was all that was on,started it up and away it went again fine,it seems to happen after about 30 minutes of running...when i put the ignition on the imobiliser light somtimes keeps flashing,so i have to turn ignition off and on again,,,i havent got a manual for it yet,so any help would be brill,,,many thanks