Did Chevrolet use promotional cars in 1969?

[William]

I have never seen any evidence of a direct marketing effort for the JL8 option. Chevy did little Z/28 marketing, only running one print ad "We've got a mean streak" which mentions JL8. Several magazines covered the release of the service package axle in '68 and a '69 JL8 car was tested by Car Life and Road Test. JL8 was delayed several months; earliest documented car was built late Feb '69. By June the option was discontinued. Little point in marketing an expensive option nearly impossible to get.

Your seats were likely spray-bombed by a previous owner.