Model-year '59 proved to be the Bonneville's breakout year. Bill Mitchell was GM's new chief of design in 1958, but was already working on the '59 Bonneville with the idea of making a styling breakthrough from the Harley Earl era. The new design came in a four-door hardtop sedan, a two-door coupe, the Safari station wagon, and the two-door convertible. The design was longer, lower, and wider, with sleek straight lines, crisp body creases, twin-fin rear fenders, and a new arrowhead logo.

When Knudsen saw the new design, he loved it but felt that the fenders draped awkwardly over the full-size chassis. Brilliantly, he ordered the wheels pushed outboard as much as possible, increasing the track by 6 inches. Many have observed Pontiac was the only '59 full-size GM car line that looked right from every angle. The marketing department ran with the concept and branded the '59 Pontiac Wide-Track. This iconic tagline lasted on and off all the way to Pontiac's end in 2009.

The new Bonneville wasn't just a pretty face. Under the hood, the Pontiac 370 was bored out again, this time to 389 ci. The base economy engine had 215 hp and the performance Tri-Power 389 had 345 hp. While that doesn't sound like much by today's standards, the new 389 Tri-Power was a torque monster rated at 425 lb-ft! It featured the four-speed Hydramatic automatic transmission, and power steering and brakes; the Safe-T-Track limited-slip rear end was optional. Front and rear 11-inch drum brakes (aluminum on the 345hp version) were considered heavy-duty then.

The interior was big and classy with plenty of bright work on the dash, pedals, steering wheel, seat trim, and tri-color upholstery. The back seat was big enough to seat three.

The '59 Pontiac was met with rave reviews and won Motor Trend's coveted Car of the Year award. Overall Pontiac sales were up 76 percent to 383,320 units. Pontiac went from Sixth to Fourth place in the car industry. Not only did Knudsen and his team turn Pontiac around, but seeds were planted that in five years would produce the first official muscle car, the GTO