It was a fighter jet, but the crux of thing was that while they advertised “hey get enough tickets, and you can get something on our ticket store, mike this military jet for xxx tickets”, the military jet was not in the store (obviously). The guy accumulated enough tickets to afford the price that was in the ad, then sued to hold Pepsi accountable for their advertisements.

IIRC he lost, because the judge went “yeah you can clearly see it’s meant as an exaggeration bye”