A plug and play LED "bulb" will not work well as a low beam replacement. What manufacturers such as Audi, BMW, Mercedes, Toyota, Honda, etc have done is developed an LED headlight system that works with both reflector and projector optics to create usable patches of light output. This is why they need more LEDs to create a similar output to either halogen or HID.
2 LEDs using reflectors for low beam output
2 LEDs in projectors and 1 LED in reflector for low beam output
Replacing your halogen bulb with something like the following will lead to bad times
