Scott Dorsey actually said:

I mean the big rubber hose going between the throttle body and the airflow
sensor. It cracks and then the airflow data becomes invalid and the car
starts running lean. You can patch the cracks with 3M weatherstripping
adhesive for a while until after a while you can't.

Oh, yeah. I know it all too well.

My first smoke test for a lean condition showed a crack on the *underside*
of that large ribbed tube. A few years later, my second smoke test showed
that the tubes sticking out had leaks.

It would have been cheaper to just replace the damn things, instead of
doing all those expensive smoke tests, which was your point, I agree!

The issue on this one is that the they are using that TO220 FET as a linear
regulator to adjust the voltage on the motor, and it develops a lot of heat
of course.

Maybe you can answer a question which has irked me for years.
As you know, the AC/Heating system is "fully automatic" meaning it's not
intended for manual control, so, the blower starts at whatever settting it
wants to start at when you start the car, no matter what setting you left
it at when you last shut down the car.

I *always* adjust that, either to *off* or to the midway position.

But what I always wondered was, if the blower is on at all, whether the
full on, or midway position caused less stress on the FSU?

I'm guessing from something a guy named cn90 and jim cash wrote that I
found by googling, that the midway position is least stressful for that
TO220 FET (there are three of those MOSFETs aren't there?).

Which blower position do you think is least stressful on that MOSFET driver
if the blower is on?

1 bar
5 bars
10 bars

In Germany it's not a problem, but in Florida it fails pretty
promptly. There are a couple places that have retrofit ones with big
heatsinks. There have been a couple people talking about making PWM retrofits
but nobody has done it yet that I know.

I know when my FSU failed the first time, it was so hot I burned my hand
trying to get it out of those Germanic clips. The second one failed without
heat, as did the others (where they failed in a way that gave the AC/heater
controls a mind of their own).

Tried Formby's Furniture Refinisher or maybe just xylene on it to liquify
the varnish and redistribute it?

Nope. I didn't know about that trick. Maybe I'll try since it's just the
varnish that is cracked.

I would tend to disagree, with a few exceptions like the cooling system
which really IS shameful.

The ABS "trifecta" failing on the E38, E39, and E46 is also shameful.
So is the trunk wiring loom fraying on almost every vehicle.
And the headlight adjusters crumbling on some of the models like mine.

I'm just a guy who likes to drive cars for a long time, and I like BMWs

Thanks for your insight.
Very interesting!