Hyundai Motor America was flying high in the late 1980s, with the unbelievably cheap Excel selling like mad (and Hyundai's CEO still nearly two decades away from being thrown into the slammer for embezzlement). The introduction of a brand-new midsize sedan for the 1989 model year represented South Korea's aggressive push into the US market. Here's a magazine advertisement for that car, serving notice to the four million Americans who bought Camrys, Accords, Tauruses, Celebrities, Dynasties, and all the rest that they'd been ripped off and should feel bad.
In those pre-SUV days, the midsize sedan was the mainstream motor vehicle here, and the Camry and Accord were the clear targets of the new Sonata. In 1989, Toyota had only been offering an optional V6 in the Camry since the year before, while the US-market Accord wouldn't get a V6 until 1995 (though the Accord-based Acura Legend had one starting in 1986). If you'd already bought one of those overpriced, underpowered competitors, eat your heart out!