I have a 2004 audi a6 sline 2.7t Q it was driving and ideling bad + engine light flashing check code P0305 cylinder 5 misfire, changed all speak plugs Oct 24th 2015 so I figured it was the coil pack changed coil pack Runs way better check engine lite no longer flashing but still on now says P0300 random misfire any ideas on how to fix the problem

 

Have you cleared the code to see if it comes back? You may have a couple hiccups from another coil that's getting weak but isn't so weak as to not fire. Clear it and see if it comes back and we can go from there.