Ok so I am not sure what is more common and how I can even check. I know i had an old Infinity that the ballast was part of the headlight that was shot and they wanted $2000 for a new headlight (they turned like the BMW with the steering wheel). Until I seen it was screwed on and ebay helped me lol. But with these are the ballasts more likely to go or the bulbs? How do I even test it?