Yes, but you only searched because you knew such a thing existed. As already said, you generally don't go searching for something you are lead to believe doesn't exist. Drive into the airport and you will not find any signs for drop off at silver zone - only drop off in short stay for £5.
Now please do something more productive with your time and help The OP out, rather than searching for free Bristol drop off that others have already demonstrated actually exists. Get searching for free drop off at Heathrow, which was the original gripe for this thread.