You think you got it bad. My ride has 15 candlepower headlights. You can hardly read a newspaper at night six inches from them.
Seriously, it all about watts. P(watts)= I(amps) X E(voltage). Your voltage is constant, so the only thing you can change is amps to get more watts(brighter lights). Have you thought about a relay. The run of the mill relay costs less than five bucks. It's good for 30 amps. A few feet of heavy wire #10 inside the engine deck with the feed wire from your light switch to energize the relay and you got it. Good luck.


Six volt guy living in a twelve volt world