Fiberglass tops. They tend to be noisy, and wind noise is directly related to increased driver fatigue on long trips. Not an ideal characteristic for what I intend to do.
And, since fiberglass tops are usually a single layer in most areas it provides zero insulation against cold, which also means they transmit a good amount radiant HEAT right onto your head.
Previously, I installed a set of
HOTHEADS headliners on the JL. I was pretty happy with them so I just did the full treatment on the Gladiator along with their Sound Assassin strips (butyl-based sound deadening material). They say their kit reduces road & wind noise by 3 to 6 decibels (dB) and I believe it.
NERD ALERT: What makes these really cool is the radiant barrier material sandwiched inside the panels you see. They use a tear-proof, heavy foil material commonly used on the construction of homes and buildings in areas such as walls, roofs, and attics.
Radiant barrier is extremely effective because of it's main two properties, Reflectivity and
Emissivity. The reflectivity properties reflect or block radiant heat (heat transferred by radiation) by at least 90%. The emissivity properties of the radiant barrier are approximately 0.03 which is great (the lower, the better). This means that the amount of heat emitted to the surrounding air is 3%.
In a regular Jeep
without this type of hard top headliner, the exterior heat and radiation from the sun will be absorbed and reflected directly into the interior and onto your body. This increases internal temperatures and makes your air conditioner work even harder to keep up. Alternatively, in cold weather, heat from your interior is easily radiated/emitted outside because of a higher emissivity rating.
In a Jeep
with this headliner, the reflectivity properties of the radiant barrier will reflect away a lot of the heat and radiation from the sun, keeping you cooler inside and putting less stress on your air conditioner system. In colder weather, the emissivity properties won't allow as much heat to leave your interior, allowing your Jeep to warm up faster on those cold mornings and to also assist in regulating the temperature overall.
Hothead Headliners are also made right here in the USA