I have a 2014 MKZ Hybrid in dark blue metallic! The window tint is a very good idea!
In high heat environments, (like Arizona) day time temps are easily 115 -120 in the summer. This creates issues with the MKZ Hybrid battery capability. Since the MKZ hybrid battery is in the trunk and high heat in the day, (ie your car is parked outside in the sun, no shade, or is used in short stop and go driving) can cause the battery to "bypass", it appears to be charging from your environmental battery charge gauge, but the lithium batteries, are offline, too much heat means no charging ability.
You know this is happening when your car mileage drops to 20mpg, which is the default capability of the 2.0 liter motor. I called Lincoln and they said, TINT your windows! Factory tint is NOT enough, they recommend one of the new ceramic tints, as they can block more UV and and heat inducing Infrared rays. This allows the Lincoln to cool much quicker once the A/C is on. This is important as the Lincoln MKZ Hybrid and Ford Fusion Hybrid li-ion batteries are "cooled" by the INTERIOR comfort air in the Lincoln from the A/C! They actually suck air out of the passenger compartment and blow it across the li-ion battery pack, then the air is channeled to exit the li-ion pack and blow across the rear trunk 12vdc instrument battery on the left rear driver side of the trunk compartment. Stunning reveal! We get great mileage in the winter, but in the worst summers in Arizona, not so much! Lincoln does not disclose these issues as most folks don't experience the issues. So, TINT, is the only real way to fix the issue! And you just did that. Congrats!
Re: THX audio, I have it and it is great! IF you develop issues with intermittent speaker failure, (my fronts would go in an out), the problem usually lies with the THX amplifier in the passenger side rear trunk behind the trunk felt. Be aware also, that at least in m case the cause was water dripping onto the amplifier due to Lincoln splash guard located under the trunk lid on the upper right corner. Lincoln's idea was to channel the water on a splash guard, but to install the guard they drilled three holes to hold the guard onto the bottom edge of the water channel. This fails almost immediately, causing water to run under the splash guard and then drip onto the THX or other amplifier, Worse the splash guard is also installed on the left side of the trunk as well, which means the water drips on the 12v instrument battery and the control module located next to this battery. As you vehicle is as old as mine, its a very good idea to pull this up, and seal the areas the three plastic push pins holding this splash guard in place. Its a minor item until its NOT! Dumb idea by Lincoln. Leaves and dirt get under this and the only place the water can go is onto your electrical connections in the car. Arizona does not get the amount of rain and snow you get where you live, so freezing temperatures, cause snow and ice to destroy the effectiveness of the splash shield over time. You can find replacement splash shields to install for about $30 each, then install with ULTRA Black RTV which can remain flexible, I used Black GE Advanced silicone (-40 to 400F) and reinstalled splash guards with a thick bead 360 on the splash guard to seal, and also into and around the penetrations Lincoln put into the body of the car, followed by reinstalling the Lincoln plastic rivets.
That's three items of critical feedback you might have to address !
A fourth is the electric A/C used on the Hybrid, if the electric A/C compressor fails its about $2,000 in parts, labor and tax to replace. You have to drop the inverter cooler, in order to remove the A/C compressor, the compressor is very expensive. Only Ford makes the part, so the part is expensive. We had to replace ours at 70,000 miles. In Arizona, as you can imagine, that AC is running year round. Might not be the situation where you live.
Good luck, we love our Lincoln, has 92,000 miles now, is a dream to drive on the highway, super quiet and comfortable, with good mileage. We have the optional sport suspension package, and can dial in, soft, medium, or firm, depending on highway vs, sport driving, (this MKZ is amazing in the curves).
