Bad Headlights

The short story: My daughter told me that she can’t see well at night in her 2012 Sonata. I had a mechanic put in what he said were very strong LED lights. I drove it in the dark after he installed the new lights and, at best, there was no improvement.

(1) This is a reliable mechanic that I’ve been using for years.
(2) At one point during this drive I drove on a very dark road (at night). The lights were so bad that I turned them off while I was driving to get a feel for how much the light were contributing to my ability to see. I literally couldn’t see a difference between driving with them on and driving with them off. On the other hand, if I get out of the car and look at the lights, I can definitely see that they turn on.
(3) The clear plastic casing that the lights are in seem pot-marked and dirty (kind of foggy-looking). Before getting the new bulbs, I mentioned to the mechanic that I thought that this might be the cause and not the bulbs themselves, but he dismissed the idea. Considering that these new bulbs didn’t help and possibly made it worse, I wonder if I’m correct. Also, what would be involved in replacing the casing and how much is that likely to cost? I did follow some directions online a year or two ago about how to clean the casing. It was a lot of work and I’m not sure if it helped at all.
(4) During my test drive I noticed that using the high beams gave me acceptable light, not great light, but acceptable. I drove the entire 10 minutes home with the high beams on. There was very little traffic during this drive, but absolutely nobody flashed their lights at me to indicate that I should turn off my high beams.
(5) Other than the lights, this 2012 car doesn’t appear to have any mechanical issues. So I’d love to fix the lights instead of getting a new car, but being a 2012, I don’t want to pour a ton of money into this car.

I would appreciate hearing anyone’s advice.

Have the lenses polished. Not a very good mechanic in my opinion.


As texases said, have the plastic lense polished. I had mine professionally done by a body shop cost (2 years ago) $80, the improvement was amazing.

If this Sonata was not factory equipped with LEDs, go back to the correct bulbs, LEDs May cause issues.


You can also DIY refurbish the lenses with a kit.
Just be sure to use a kit that includes a protective coating, not just polishing.
I’ve had good results that last several years with this kit:

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I have installed new aftermarket headlamp assemblies with Silverstar halogen bulbs on my 1999 Honda and 2007 Chrysler van. They make the cars look almost like new, and they illuminate better than worn and polished original equipment.

LED bulbs are a gimmick if halogen is the original equipment. They do not help.


I got the aftermarket headlamps from Rock Auto; less than $100 each as I recall. It took me about an hour or so to replace each original headlamp. The van was especially easy. The Honda needed more disassembly.

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Beyond polishing the lenses, I suspect you need to aim the headlights. If they’re pointed too low, they’ll only illuminate the road directly in front of the car and not farther away. There should be a pair of adjusting screws for each headlight assembly. You can find instructions online.

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Projector lights are usually adequate light. Buffing the exterior shell might help

If the plastic covers are hazy, there is a YouTube video where very bad ones were cleaned perfectly with WD40. I can’t verify it, but the video looks legitimate.

Come back and let us know what you did.

First thing to try would be polishing/restoring the exterior surface of the headlight. The off-the-shelf lens restorer products work very well, all with a goal of removing the exterior oxidised/UV damaged layer of the polycarbonate.

The best of the easy & quick ones I’ve used is the CRC Headlight Lens Restorer.

I’ve tried the Turtlewax multi-step restorer pack (which is essentially a progressively finer grades of polishing pads & compounds) which gives a superb & crystal clear finish but it’s a tedious & physical process. The one-step CRC cream did almost as good a job in only a few minutes each lens.

Generally will require redoing every year or two.

(Btw WD40 does not work. All it does is leave a film on top that makes it appear clear but it will evaporate and weather off leaving it exactly the same.)

You can use polishing compounds (such as for paint or aluminum polishing paste) with a power polishing pad but the purpose made creams like the CRC do a great job.

The only thing polishing can’t fix is the micro-cracking and crazing that polycarbonate develops internally & on the surface over time (different from the fogging/hazing of the surface) but at under $10 the products are worth a try.


Are you sure thet your headlights are being illuminated and not just the DRLs? Also check aim. on a level driveway the center beam of each high beam should hit a garage door at the same height as it is on the car.

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Seems the OP has chosen to not respond.
Changing bulbs on a Sonata is a two minute job, but the OP had to take it to his mechanic, do you really think he would be able to polish his daughter lenses or aim the headlights?

He may not be able to polish the lenses or aim the headlights but he should be able to tell if his low beam headlights are illuminating by looking in the lenses or tell if they are aimed too low by shining them on a garage door at night. Neither of those require any mechanical skill or tools.

Having clear lenses and aimed headlights are the starting point, but some cars just have lousy headlight designs that bulbs are not going to solve. BTW where I’m from putting LED headlights in a car not originally designed for them is an illegal non-OEM modification.