The Bonneville was all new for 1958, with completely redesigned bodywork on a Cadillac-based cruciform frame, and a hardtop version joined the convertible in Pontiac showrooms. Coil springs replaced the old semi-elliptical units in the rear for an improved ride, and a shorter platform offered improved handling, which the Bonneville took advantage of with a new 370 cubic inch 4-barrel engine packing 10:1 compression and 285 horsepower with the 4-speed Hydra-Matic.
Story by Mecum Auctions

Auction Sales History

1958 Pontiac Bonneville Tri-Power Convertible – sold for $126,500. This Bonneville is a glowing example of the legendarily dazzling aesthetics that swept through American car design during the late 1950s. Its Mallard Turquoise paint shines with warmth, wonderfully enhanced by the Tri-Power badges that announce the engine’s strength and the stark contrast of the white and chrome trim. Meticulously detailed chrome dominates its visual façade, from intricately cast side-view mirror housings, to delicate spears and stars that adorn the beltline moldings and rear fenders. Furthermore, the engine compartment has been cleaned and detailed to perfection. Auction Source: 2011 Scottsdale Auction by Gooding & Company