1989 was the last chance for Coe and Aouita to meet, and it's mystery why they didn't. I would favour Coe in that year, actually. Aouita was certainly slowing down and the East Africans were starting to take him on. This classic race from 1989 Stockholm just uploaded to YouTube.
Would you say Aouita was losing his speed in the 1500m by 1989?
Though he did run a 3000m WR in the same year.