Park Avenue remained the top trim on the Buick Electra, it was redesigned along with the rest of the Electra line up moving to the front wheel drive GM C-Body. It featured upgraded upholstery/seating, premium sound, optional leather, and standard Buick 3800 V6.

The coupe version was discontinued in 1987. For 1989, Buick introduced the Park Avenue Ultra trim level. The Ultra was essentially an upgrade to the Electra Park Avenue line, and featured a standard leather interior with dual 20-way power front seats (shared with Cadillac's restyled 1989 Cadillac Fleetwood Sixty Special), lower-body accent exterior paint treatment, distinctive thick-padded vinyl top with limousine-style rear-window surround (available only on Ultra), simulated burled elm trim on the doors and instrument panel, unique aluminum wheels, anti-lock brakes, chromed B-pillar moldings, specific grille and tail lamps, leather-wrapped steering wheel, electronic instrumentation, padded glove-compartment door, unique interior door panel trim, and a variety of otherwise minor changes.

With its long list of standard equipment, the Park Avenue Ultra carried a higher base price than Cadillac's Sedan de Ville. The Park Avenue Ultra did not gain much popular recognition, however, until the following generation of Park Avenue where the "Ultra" badge offered even more features.