Because the tag itself is pretty much in the shape of the bag, I think you're correct that it's for older model cars.
What does the owner's manual say about operation of the windshield washers? Do you have the floor button pump style or the push-in at the wiper switch electric variety. Because the w/s reservoirs were translucent plastic, it became much easier to determine the fluid level and Chrysler's hope was that it would be self-explanatory to the car owner/user. That wasn't always the case, hence the addition in later years of an "idiot" light in the instrument panel to warn drivers when the reservoir was running low.
