I'd think initially as said, the wiring would suffer in a bad way, followed by the lamp holder and then the plastic light covers. Of course Plod might just catch you in time and save you some of these problems - these wattages are not provided or permitted for use on public roads - well in UK anyway.
The 100watt is the electrical power consumed by the filament, the output will be rated in Lumens, I'm guessing that you are quoting a "50%+" model of bulb.