Question: Which midsize car  of 1973 to 2005 used a shared platform with Pontiac 6000?
Sentence (from "Buick Century"): Buick Century is the model name used by Buick for a line of upscale performance cars from 1936 to 1942 and 1954 to 1958, and from 1973 to 2005 for a mid-size car.
Relevant evidence: Yes