They for sure look pretty bright, but keep in mind, that most of the higher power LED-Chips can Actually MAKE YOU BLIND, because of how powerfull they are (if watched too long directly from Short distance). If i could take a guess, i would say that those Car-LEDs propably are 5 to 20 Watt each at max. that is sure bright for any light on a car, but not so bright compared to those High-Power LED-Chips.... The "classic" ones, that have been around for many Years have 100W Power, Now there are even Newer Versions with 200, 300, 500 and seemingly even higher Power Versions Like 1000 Watt! Just watch the video, which i linked in the other thread from the Beyond the Press chanel on YT. Those Lights are so bright, that they needed to wear two pairs of Sunglasses to be even able to see anything, because it just was THAT bright. Those are no joke. Pretty sure that LED-Setup they used to Light the Chronos Ring Footage would be able to overpower the sun by quite a bit at that distance....
However, i would seriously be impressed if any LED for Cars had more than 20 to 40 Watt. Additionaly, like SergeyKashin allready said, they most likely have pretty bad color, since they just need to make it bright, and your eye doesnt care that much about Color, but cameras do very much. Most of those cheaper LEDs, which are most likely used in those Car ones will not be a proper white color, but rather a bit green tinted. You Could Propably still use them (i did use cheap ones, but its a pain...), if you know very well about this, and how to correct for it, but as soon as you have mixed Lighting Sources (Sunlight/ tungsten), you will clearly see the green color cast from the Cheap LEDs. That is one of the Reasons, why Bright and high Quality Professinal LED-Lamps built for Cinema and Photography tend to be rather pricey, since they (mostly) use the more expensive LED-Chips with better color (higher CRI=Color rendering index)