There are many different LED kit series. When shopping for an LED kit you should know where you want to install it (low beam, high beam, or fogs), how much space you have behind the headlight, if you have a dust cap(s) on the back of the headlight, and the bulb style to fit the application. All Dodge, Jeep, Chrysler vehicles require use of canbus decoders with LED kits which prevent the LEDs from flickering or shutting off after short time of use. Ford, GMC, Chevy, and most import vehicles are not affected. However there may be exceptions. For example, installing LEDs in a KIA Optima requires that you use canbus decoders.
What kit is best for my vehicle? LED bulbs vary in sizes, cooling type, LED driver location, bulb style, and optional beam adjustment which is not available on the cheaper LED kits (example: C6 series). Start with looking at how much space you have behind the headlight. This will determine the LED Series you can use. If you have a lot of space and no dust caps, you can pretty much select any LED kit. If size is limited you will want to select the smallest possible LED body series like X3, reversible cooling 7G, or 8G. If you're installing the LED kit under a dust cap with very little room then select the G10 series. If installing under a dust cap with more space the 8G series seems to work well.
Cooling types - there are a few different types of cooling found on LED bulbs. These are copper ribbons, fans, and ribbed cooling fins. Generally speaking the more light output the LED has the more cooling it will need. For example 8G LED kit with 12000lm requires a fan to cool the bulb. Most 6000lm and some 8000lm LED kits are fan-less and use only cooling fins. These are best suited for fog lamp installations where there might be water, snow, ice, and mud thrown at them. Fanned bulbs would not do well under these circumstances.
How hot do LEDs get? Not as much as halogens or HIDs. In a short test, halogen and HID bulbs reached temperatures over 300C while LEDs hovered between 80C-100C. LEDs do get hot to touch but they will not melt a vehicles' headlight or fog light housing.
LED drivers - there are only 2 types of LED drivers, built-in LED drivers found in all-in-one LED bulbs, and external LED drivers, similar to HID ballasts but much smaller. Use of LEDs with external LED drivers limits the installations to headlights where there is room to mount the LED driver. Some headlights are large enough so the LED driver can fit inside them, and the dust caps can still be closed. Others are too small and require the use of an all-in-one bulb to fit under a dust caps.
LED adjustment - not all LED bulbs have an adjustable beam. What this means is the you can rotate the LED body in the headlight so the LED chips face 3 and 9 o'clock for best projection. Some vehicles may require the LEDs to be at 12 and 6 o'clock. Having adjustable beam gives you the ability to adjust the light so you get the best light pattern and reflection from the lens in your vehicle.