[Sienna]

Bill you are correct in your assessment. Your second picture with the black rubber coupling is also some thing I am considering. I will have the trailer open next weekend and hopefully can fix it on my last day camping. The actual trap is in front of the water heater behind the left door of the sink cabinet. I plan to buy a bunch of parts from Home Depot. Returning what I don’t use after the trip.
Ideally I install the silver part and screw the pipe on and I am done.
The picture with the silver drain came from TrailManor they sent the picture before they sent the part. I believe in there picture they are using a hepvo trap the white piece on the right of the picture, not the corrugated piece.
One more picture from TrailManor also included.