Anatomy of the 2013 tail light
 

Weird question... are the led's in the tail light sealed behind the outer lens?
Reason I ask is my car was caught in a hail storm and now I have a hole in each tail light at the bottom of the reverse light in the black. If water was to get in will the lights themselves be ok?
I'm working on getting new ones but they are so freakin' expensive.

I had a crack in one of my lenses that let a lot of water in, The leds worked just fine but looked dimmer where the water was covering it.

I recently broke the outer red lens cover to my 2014 taillight and can offer a comment. With the red lens fully removed the 3 light LED "package" is retained in the taillight assembly with 4 screws. The LED package is exposed and is not sealed in any way. Integrated circuits and electronic components are on exposed circuit boards behind each of the 3 LED lights. Thus I would say that if a significant amount of water did get into the taillight it would definitely cause electrical problems with the circuit boards which are unprotected. Also the electronic components on these boards are loaded to the bottom of the light thus making them more susceptible to a rising water level in the lens.

As I have to replace my unit as well and knowing these lamp assemblies are expensive, where is the best place to purchase a replacement?

Probably eBay

I have heard to be careful on Ebay because some are trying to sell these lights with halogens instead of the led's(correct me if I'm wrong). Also some may be sold with faulty LEDs so be careful there.
I used to work for Latemodel Restoration so I get everything from there since it's right down the road. I'm playing it safe and saving to get the OEM replacements from them so theres no question what I'm getting.
Right now I put some electrical tape over the holes and honestly you can barely tell it's there 🤣 but it keeps the water out for now!

Thanks for the advice Waco 5.0.

Anytime bro

The 13-14 cannot be sold with anything but the LED's, the 10-12 have replaceable LED's so those might be the ones you were thinking about.

Here's what I'm talking about...
https://www.carparts.com/details/Ford/Mustang/Replacement/Tail_Light/2013/GT/8_Cyl_5-dot-0/REPF730192.html?TID=gglpla&origin=pla&gclid=Cj0KCQ jw5s3cBRCAARIsAB8ZjU052reE29NflQiPXSmlpGDiZXkmBwJI mvodH2vKyMKbV7ybs-toJX4aAqYuEALw_wcB&gclsrc=aw.ds

Ford remans these lights, check with a Dealer.

That listing is probably wrong. Even it it wasn't LED, it would be Incandescent, not Halogen. You wont find Halogen bulbs in any taillight, side-marker, or turn signal. The only place that is a possibility is a retrofit in some reverse lights, but not on a 2013-2014 since its all LED.

If possible, Contact the seller to verify. However, looking at the back of those, I don't see any way to change bulbs which increases the chance that the listing is wrong (or the pics are wrong).

If you want to change up the appearance, here are two options that borrow style from Ford GT (and some other cars like Ferrari):
https://www.americanmuscle.com/raxio...ghts-1314.html
https://www.theretrofitsource.com/13...il-lights.html

I'm tempted to try this new style.

I've seen those "ring" tail lights on a local S550 model and to me they look ricey with the rotating ring animation replacing the inside-to-outside sequential turn signal... almost like something you would see on an Altima with dozens of decals on it for products that obviously aren't installed.

Holy Carp!!!

1,100 Bucks for a single tail light assembly?? (OEM)

Whatever happened to light bulbs? Can't see why the LED craze is taking over the automotive lighting systems with that sort of cost involved.

Improved lighting for us, increased profits for them.

I'd love to see standardized replacement LED for headlights and taillights agreed by OEMs and lighting companies. So we can have improved lighting but still have a relatively inexpensive component to replace instead an expensive paperweight when things start failing in 10yrs.

There are aftermarket drop-in replacements to work in place of original bulbs in places with varied success, but that is a separate topic.