I do not know that is why I asked the question. The retainer ring has a plastic or acrylic frame around it.
According to the 1997 Mercury Villager Owner Guide : The jack is behind a removable plastic panel , in the cargo area , on the passenger side ( there is also the tool kit with the lug wrench )
You have to disconnect the whole headlight assembly with the headlight attached. Remove all the bolts from the assembly and pull it out with the headlight attached.You may have to move things out of your way,like the corner blinker light and plastic trim. When you get the assembly out with the headlight attached,there are 3 black plastic retainer clips holding the headlight to the assembly. Push the tabs on the sides of the retainer clips to release them then pull them out. The headlight then comes out,don't damage or lose the retainer clips,they are almost impossible to find cause they must only come with a new headlamp or assembly because I needed some and noone had any, not even Infiniti dealer. I had to go through many Nissan's at the salvages to find some.
Raise the hood and on either side there are two 7mm bolt heads, on top of the metal frame, pointing downward. Remove these two bolts (one long and one short) and this will release the headlight unit. Pull it out far enough to unplug the bulb and turn the large plastic retainer nut and remove the bulb. The headlight unit may be caught on the plastic cowling and you may have to depress the plastic cowling in order to slide it out. You also may have to release the two plastic retainers that hold the top of the plastic cowling to the metal frame. If you do, pop up the centers and then remove the retainer. Cowling can then be moved enough to get the headlight unit out.
It is under the black plastic trim plate under the windshield wipers.
open the hood, remove 3 screws on each headlight and pull the headlight straight out, unscrew the black plastic cap, loosen spring retainer but don't remove it. install new bulb and put it back together.
You are probably referring to the piece under the front bumper. That is a stone shield. It is held in place by several plastic rivets and metal screws.
there are two Phillips screws in the plastic bezel and then two push in clips that are part of the plastic bezel.After you remove the plastic bezel there is two screw on the top and two on the bottom of the metal retainer ring that hold the light
Intake Air Temperature Sensor. Located in the plastic air intake tube beside the battery.
The intake plenum is simply the top of the upper intake manifold, where the throttle body is attached. It is made of black plastic.
Under the hood below the headlight is a black plastic assembly. There is one plastic wing nut. This is the adjuster for the headlight.
Mercury doesn't react with plastic materials.