Looking for anyone who might know if these supposed 4 cars exist or if anyone here (promotion was in Canada only) won one or knows someone who did! Thanks!

 

The 7 Up company was privately owned by its founding families until it was sold in 1978 to Philip Morris, which sold it in 1986 in two parts: the international division to PepsiCo and the US business to a group led by the investment firm Hicks & Haas.

You can try reaching out to Philip Morris .. however their records may or may not go that far back.

You could also try reaching out to the publication who ran the advertisement. They might have had a followup story announcing the winners.