You can only tell properly with the car up on a hoist. The leak may be
muffled by the car structure. If it's vibrating, this implies that the
exhaust is loose at the manifold, since this connection is one of the
vibration dampers. Easy and quick repair for any of the big volume exhaust
franchises. Routine maintenance on any 5-year old car.

There is one way to tell if you have a hole in the muffler box or exhaust
system, you can pop down to Midas for a free check up or block the exhaust
pipe when the car is running. (You can use your hand with a work glove on).
If there is a hole or a split in the exhaust system you will hear it from
the hissing noise and the car will not stall out. If the car starts to stall
out when the exhaust pipe is blocked, then the exhaust system is intact with
no holes. There is a problem with this exhaust system,  that over time it
has a habit of rotting from the inside out. One way to tell is check for
rust stains on the inside of the exhaust pipe or rust stains on your drive
way from the exhaust condensate. (its happening to mine, exhaust starting to
get loud),

BRibic wrote:

only seems loud from inside. Vibrates a lot.