Vintage 1980s Whataburger Plastic Nickel Coffee Mugs

While many are familiar with the Butterscotch glass Nickel Coffee Mug (last picture), perhaps they're not as familiar with the plastic mug that was also released during the 1980s for the projected one-year promotion (you buy the mug and for one year they'd let you fill it with coffee for a a nickel [5 cents]), that ended up running, and being honored for about 14 years.