The criminal was the cyl 4 spark plug wire.  After replacing, the car
is running very smooth.  So, if your car starts shaking after driving
in the rain or going through the car wash, check the ignition wires.
I wish they sold single spark plug wire AKA ignition cables.  They
only sell them by the set of 4 or more.  So, I had to buy all 4 and
throw away 3 of the old but working wires to accommodate the brand new
ones.  What a waste!  There should be an agency looking over the
possibility of reducing waste by forcing part manufacturers to sell
single wires.
To test bad wires, start the engine.  Use rubber gloves and insulate
yourself from the ground by standing on a dry piece of wood.  Very
carefully remove one of the spark plug wires.  If that wire was
working properly before removal, you will hear and feel a significant
performance drop in the engine.  Put that wire back and the engine
will start running smooth again.  Do one wire at a time.
Do not disconnect more than one wire at any time.  Make sure you take
a digital photo of the engine before starting.  So, you will know
which cable goes where, in case you mess up.  You may see sparks
flying from the end of the removed wire to the engine body if you are
not careful pulling it out.  Make sure you do not have a gas leak or
anything flammable around.  The sparks may ignite them.  Also check
the resistance of the wires in kilo-ohm to make sure they are within
your manufacturer's recommendation.  Rule of thumb for many passenger
cars is: the resistance has to be less than 10 kilo-ohm per foot of
spark plug wire to be acceptable.  The ignition wires are made from
carbon impregnated nylon strings.  They carry less current than metal,
but are more flexible, significantly reduces radio and electro-
magnetic interference.  Common sizes are 7mm to 8.5mm in diameter.