I have an 2005 road star. I found a pair of 7 auto headlights for 1/2 the price of one motorcycle headlight. it should fit the bucket but what about the 12 volt system?
Well you just have to make sure of the Hi-Lo wiring, but the bike is 12 volt right! the car is 12 Volt. Shouldn't be a problem. And if they dont Quite fit, I always found duct tape works great Remember: spare the duct tape spoil the job.
The problem will be in the bucket. The clamping system to hold the bulb is different. Still works though. Did the same on my old Suzuki. I preferred the wide, flat beam of the auto bulb over the narrower motorcycle bulb. $4.99 for something I liked and that lasted, or $29.99 for what wouldn't last a week. Tough choice. Hot melt glue took care of the mounting problem.
Most bike headlight bulbs are auto parts mounted in custom housings, and replacements can be bought off the shelf at AutoZone or Poopboys. My light I've run for the last 25 years is like that. In fact, some of the original custom chopper headlights were bolted up right off old antique cars like the old bullet light Chevy's and Model A Ford's. All electrics, both Bike and auto nowadays are ALL 12 volt systems.