Touareg starts and stalls
 

Hi , this is my second time that my 2009
Touareg with 4600 miles starts and stalls.
The problem is the the exhaust gets filled
With water and freezes overnight on low temp.
Field engineer at VW advise vw tech to drill 1/8 weep hole at the lowest point of both the rear muffler and mid pipe resonator...this is to allow condansation to
Drain before the exhaust will be restricted
Again with frozen water . I would like to know your opinion in this matter and my concern is that the muffler will get rusted or will be more noisey with those holes.
Thanks Again