"This made a big enough impact on your day to warrant starting a thread about?"
Well, the thread made a big enough impact to get 18 replies so far, so if that's anything to go by, yes.
"…fat middle aged IT manager decked out in lycra sitting on his bike behind her"
Did you miss this bit;
"Driving through Bewdley today…"
And I'm a fat, middle aged bus mechanic, I'll have you know.
"How do you know she was shaking her head at the motorcyclist?"
I did wonder that myself at the time, but as she was in an open topped car I got a good view of her head movement as she watched the bike go past and that theory best fits the evidence.
I can only presume what the driver was thinking, but after all the "I saw a motorcyclist doing something naughty, therefore all motorcyclists are naughty" and "Don't do anything naughty on your mountain bike because then car drivers will think we're all naughty" threads, it came as first hand experience of watching someone tut tutting at a motorcyclist causing a minor hold up, then finding it acceptable to do almost exactly the same thing themselves.
I guess you city types see this sort of thing every day. It was a bit of a novelty to me.