Mopar Dufuses in the 80s

Back in the late 60's visiting with my cousins in Farmer City for the weekend, bored. Cousin Steve suggested we hop on the ole Schwinns and pedal our butts up to the square for look-see. The cars would seamlessly drive around and around the square and disappear briefly and back again. There was a red car that was making this odd noise as he cruised around the town square, tinkle noise, like loose change in a dryer. I notice the faster he drove the less noise it made. Asked Steve what the noise was about he said, pebbles in hubcaps...I guess it was to draw attention to himself....dufus.