Question: Which midsize car  of 1973 to 2005 used a shared platform with Pontiac 6000?
Sentence (from "Pontiac 6000"): The Pontiac 6000 is a mid-size car that was introduced by Pontiac in 1981 for the 1982 model year, positioned between the smaller Phoenix and larger Bonneville (previously the Le Mans).
Relevant evidence: Yes