I need some LED headlight bulbs for a 2014 mustang, the factory ones are the HIDs with the big block thing D3S or whatever which is $100+ per pair

 

Look around you can find the HID Cheaper and I have not heard of anyone replacing the HID bulb with a LED since the housings are not made for them.

 

Correct. You'd have to completely replace the entire assembly for the LEDs to work correctly, assuming there are such LED assemblies. The arc pattern is designed with the reflector, so if you put something in with the wrong pattern of light, you get bad lighting, and worse you glare out the other drivers.

Which, if you're a jerk, is fine, be a jerk to the other drivers. Personally, I'm not inclined to do that, but you do you.

Also, it's possible the car will complain if you don't use HID. All that sensing of resistance and boxes what not. And wiring up the LEDs vs the HID circuit may or may not be... fun.

 

Fair enough, but can I find HID bulbs for less than $100

 

Edited:

Sure.