I see your point about a such a large load, but I was thinking about it this way (copied from my other post):
"Those super bright lights that end up blinding people on the streets aren't properly marketed. They advertise them as a simple replacement bulb which just end up producing a ridiculous amount of light scattered in all directions. The proper ones are real HID lights, use a ballast, focus the light as not to be too bright for other drivers, and cannot be dual filament (since there is no filament). The attraction to the falsely advertised "HIDs" I guess is that the driver has dual filaments.
With a 12v source, a driver would be able to control the brightness with a simple switch to either engage or bypass a voltage divider that would serve as an intensity control (high beam - low beam). That's what brought me to do some light reading on the matter. The appeal of having the control to have 2 levels of brightness is what makes those super bright falsely advertised "HID's" so appealing. "
I was just sick of thinking that ETs space ship came back to earth every time i saw one (especially in the rain). That's what got me thinking about it.
Perhaps the (approx.) 30 watt bulb that the ballast drives is still too large to make this possible. Im no EE and still am not sure where that magical power comes from and if its safe to regulate it from the supply. Anyway this was just something I thought about and wasn't able to get a answer on by myself. Kind of like a kid who doesn't understand politics asking why the government is so (insert your political belief here).