Complex sentence: The Town Car nameplate was first introduced in 1959 Continental Mark IV lineup as a top-of-the-line 4-door sedan; the nameplate became a permanent part of the Continental lineup in 1969, denoting its highest-trim interior package.
Split into simpler sentences: The Town Car nameplate was first introduced in 1959 Continental Mark IV lineup as a top-of-the-line 4-door sedan. The nameplate became a permanent part of the Continental lineup in 1969, denoting its highest-trim interior package.