2007 BENTLEY CONTINENTAL GT Engine And Engine Cooling Problems

I HAD TO REPLACE THE WHOLE LEFT SIDE OF THE EXHAUST BECAUSE IT WAS MAKING A LOUD RATTLING NOISE WHEN THE CAR IS ON. THERE IS A SOME SORT OF FLAP IN THERE THAT BECOMES LOOSE AND IT IS NOT POSSIBLE JUST TO REPLACE THAT FLAP SO THE WHOLE EXHAUST HAD TO BE REPLACED ON THE LEFT SIDE AT A COST OF $2,000. THE BENTLEY SERVICE MECHANIC SAID THAT THIS IS A VERY COMMON PROBLEM FOR A BENTLEY CONTINENTAL GT MADE BEFORE 2009 AND THAT I SHOULD REPLACE THE RIGHT SIDE EXHAUST NOW BECAUSE THE SAME RATTLING WILL START ON THE RIGHT SIDE AS WELL. I DIDN'T SPEND THE EXTRA $2,000 TO REPLACE THE RIGHT SIDE EXHAUST AT THIS TIME. BENTLEY MADE THAT PART REPLACEABLE FROM THE YEAR 2009, SO THAT THE JUST THE FLAP PART CAN BE REPLACED AND NO NEED TO REPLACE THE WHOLE EXHAUST. THIS SHOWS THAT...