Is the movie 'Battle of the Bulge' based on facts?

Just watched the Battle of the Bulge with Henry Fonda. At the end of the movie the Americans send barrels of oil down on the German Panzers setting them all on fire killing the the German Panzer commander. Was there any truth to this in the real war? In addition in the movie there was a complex underground German bunker somewhere along the lines. Did Germans have bunkers that larger and complex near the lines? Seems a bit far fetched. Finally, the tank turrent was blown off of Telly Savalas tank and two of the crew survived to drive away in the tank. Is that even possible?