Suzuki: Water Leaking from Exhaust, internal combustion motor, oxides of nitrogen

Question
Hi i have a 2001 reg Grand Vitara, which is leaking water from the exhaust, we bought it 2 weeks ago and the garage said they had checked it and it was because it had been standing... We have now been told we need a FULL new exhaust. Would the garage have been able to tell this was on its way out...or is it just one of those things?

Answer
Let's talk first about the moisture and where it comes from.  When an internal combustion motor burns gasoline, the hydrocarbon becomes carbon particles, carbon dioxide, carbon dioxide, oxides of nitrogen, a very small amount of oxygen, water vapor, and a few other things that are of very little consequence as far as our purposes are concerned.  After passing through a catalytic converter that is sufficiently warm, and "fired off", the carbon monoxide and oxides of nitrogen are converted, and the exhaust is somewhere near 15-20% carbon dioxide, Nitrogen, and some water vapor.
The vapor condenses initially in the cold exhaust, especially the muffler, and the rear portion of the exhaust, until it becomes warm enough to vaporize the water.  This rear section will warm up last simply because it is at the back.  This is why short trip driven vehicles have the muffler go bad more often than cars that go further, especially on the highway.  
I would require that they allow you to inspect it, and that they show you (with understandable explanations)the perforated portions that require replacement.  
Does it have the typical raspy hole in the muffler exhaust note?  Or is the exhaust so severely perforated that the exhaust is too diluted with outside air as to prevent a valid sample for a state or federally mandated emissions test?  Midas and other muffler and brake shops are infamous for selling work that is not required by stating that if the required (by theirs, but not necessarily industry wide standards accepted by ASE certified master technicians) work is not performed, they cannot offer any warrant, thus implying that everyone else in the industry adheres to the same standards, which is a blatant falsehood.
If you have more questions, please feel free to ask until you have all your concerns answered.
scotty