The circumstance you describe is not usually a case of integrator windup, just the normal (LTI) dynamic, how much overshoot it exhibits.
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Integrator windup is a nonlinear process, where the integrator has positive and negative saturation limits beyond the input range of the plant being controlled. Typically this arises due to internal nodes (e.g., a multistage amplifier where the internal node has a range of state outside your control), or due to explicit nonlinear elements added to the control loop to provide additional functionality (e.g., the wired-OR diodes in an analog bench supply).
A complementary process is slew rate limiting, where the integrator cannot move fast enough to match the input -- this is typically a saturation process earlier in the chain (i.e., in a diffamp's input or volt-amp stage).
Incidentally, note that traditional dominant-pole-compensated voltage mode op-amps are "leaky" integrators, in and of themselves -- they have a dominant -20dB/dec frequency response, starting from a quite low frequency pole, with reasonably high DC gain (say 0.01Hz-1kHz and 60-140 dB).
With definitions cleared up -- where else might we expect windup?
To use the same example, we might actually expect it for a sufficiently steep upwards hill (where the cruise control would be flooring the throttle), assuming the control is designed for full control authority of course (which it might not be? I wonder).
Note that, for a given RPM, the engine is only capable of so much torque at full throttle, and it reaches nearly this torque (say within 90%) at some fraction of full throttle. This happens because the engine isn't drawing its maximum intake flow rate, so the partially-opened throttle has little pressure drop, and the manifold air pressure is nearly atmospheric.
This won't be so noticeable in an automatic car -- the transmission will downshift when high throttle is demanded, increasing engine RPM and extending the useful throttle control range. It is noticeable in a manual car, especially in an especially high gear (low engine RPM) for a given cruising speed, where torque maxes out quickly with respect to throttle range.
We might also expect it for a
downwards hill, where the throttle backs off completely (the hill is steeper than the vehicle's "glide slope" and it accelerates), then comes out of saturation as speed returns to nominal.
Incidentally, between automatic and manual cars, the cruise response is quite stark -- the automatic must take account of the slow throttle, torque converter and transmission response. The whole thing is a squishy mess, and this decouples throttle input from wheel torque and therefore speed change. In control terms, there are additional poles in the system. Typical cruise controls have a dominant pole around 1Hz.
Manual cruise controls can act much faster, and indeed could even be designed to use engine RPM instead of ground speed, or even a phase lock to a DDS (which corresponds to a position lock with respect to other traffic going the exact same speed*). Throttle response of a traditional engine is pretty straightforward (having a dominant pole in the maybe 5-10Hz range) so the cruise can be much more stable.
*Although, unfortunately you'd never see this in practice due to variations in tire size and inflation, for example.
Modern auto transmissions with locking gears should be able to do this as well, but I don't know if they are made to.
And the less said about CVTs, the better?
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The one of those I test drove, the whole traction system (since it's fly-by-wire and not meaningfully an engine and transmission, but a whole system unto itself) had a dominant pole of fractional Hz, very unpleasant to drive. (I suspect a lot of that is intentional -- psychology. Mass produced things have a ridiculous amount of psychology driving their design, no matter how stupid. CVTs with simulated gears, for example...) Unclear if the cruise would be integrated into that system (and therefore the CVT can be set to anticipate the "intent" of the cruise control), or external and therefore even slower still (with a plant of fractional-Hz, the control would have to roll off at 100s mHz!).
Tim