If you haven't done your required maintenance (such as coolant flush) on your 16v powered TC, you could end up with a severely corroded thermostat inlet.  These are extremely rare.  RDI has a very limited supply in stock.  NOS Mopar, new in the box.
 
Note this is only the left half of the housing (as you look at it from standing in front of the car).  i.e.  this is the half of the housing that the upper radiator hose slides onto.