Drain holes in the exhaust? umm..yeah...ok.
There is a catalytic convert and a DPF on all TDIs...oh yes and an adblue system that squirts a 70% /30% mixture of water/urea into the exhaust after it goes through the cat and the dpf.I just checked my T3 TDI, don't see any weep holes in the large suitcase muffler. But maybe TDIs don't need them since there's no catalytic converter generating lots of byproduct water...
They didn't have cat's for the longest time, I think they were introduced across the TDI range in 2004.