Complex sentence: Cadillac's first foray into smaller cars, the 1975 Seville, intended to answer the sales threat from Mercedes-Benz luxury cars, was a relative success, but the political and economic climate of the 1980s suggested a need for something smaller.
Split into simpler sentences: Cadillac's first foray into smaller cars, the 1975 Seville, was intended to answer the sales threat from Mercedes-Benz luxury cars. The Seville was a relative success, but the political and economic climate of the 1980s suggested a need for something smaller.