One of the reasons that a car bulb is slow to reach full output, is that
the
filament has to be made thick and robust for enhanced reliability and
failure proofing from vibration. That makes it have substantial thermal
inertia, so much so that you can indeed see it hot up. On the other hand,
high voltage domestic lightbulbs have no such constraints on their
filaments, as they are not going on and off all the time like a brake
light
or indicator, and are not subject to vibration in normal use. This results
in the manufacturers being able to design them with a much more delicate
filament, with the result that, to all intents and purposes, the ramp up
to
full output is 'instantaneous'.

I don't like disagreeing with you, but this is incorrect. You can easily see
the "ramp up" of household incandescent lights. It's about 1/10 of a second,
and is plainly visible. Some CFLs are (at least visibly) "instantaneous".