Yeah, I think the bulbs they used are generally all the same, but the physical cruise control switch and foglamp switch are only similar but not the same. For example, the foglamp switch has "dedicated" position of ON and OFF, with ON position = Slightly pushed inward. On the other hand, the cruise control switch stays at same position whether the system is ON or OFF, you can't feel if the button is slightly pushed inward when the system stays ON.
The "red cover" of the cruise control is not wired up (because there is no bulb), and the brown connector at the back of the cruise control switch does not have a terminal for the "red cover". So even if I wire up a bulb under the red cover, it should do nothing.