Complex sentence: Mitsubishi planned to sell 25,000 units of the Diamante per year to 18 countries, prominently United States where Mitsubishi positioned the Diamante as a "near luxury" car that competed on price with vehicles like the Lexus ES 300.
Split into simpler sentences: Mitsubishi planned to sell 25,000 units of the Diamante per year to 18 countries, prominently United States. In the United States, Mitsubishi positioned the Diamante as a "near luxury" car that competed on price with vehicles like the Lexus ES 300.