* Other GM wagons from the same era: Buick Century wagon, Oldsmobile Cutlass Cruiser wagon, Pontiac 6000 STE wagon (though the STE had a more aerodynamic fastback-ish rear). These were all built on similar platforms and would share a similar general roofline profile.
* Competitors from other manufacturers: Ford Taurus wagon, Mercury Sable wagon, Chrysler LeBaron Town & Country wagon (though these might have slightly more rounded roofs). Again, the similarity wouldn't be perfect, but the overall boxy station wagon shape would be comparable.
It's important to note that finding an *identical* roofline is unlikely. Even within a single manufacturer's lineup across model years, minor styling tweaks always occurred. The above suggestions are based on the general class and era of the vehicle, resulting in similar, but not identical, roof profiles.