“Offering reasonable grounds for being believed,” is how the Merriam-Webster Online Dictionary defines the word credible. Being credible requires a commitment and requirement to live up to expectations. Pontiac’s G8 is a credible competitor to some of the best rear-drive performance sedans on the market, but there are still a few nagging problems that keep it from blazing a new trail or, for that matter incredible.

One big plus is the exterior design. Gone are the blandness and other foibles that plagued the brand’s last attempt at a rear-drive sports car, the GTO. The G8 is aggressive yet tasteful, with an almost European leanness to its flanks. The front fascia is accentuated by Pontiac’s version of the twin-kidney grille and a pair of hood scoops that not only will make the Pontiac faithful happy (they complained incessantly about their absence on the first year of the last-generation GTO) but signal the power to be found under the hood without being cartoonish. Overall, the G8 is very sleek and modern, with a long wheelbase, short overhangs, and a dash-to-axle relationship found on the best rear-drive performance sedans. Its wheels-to-the-corner stance has overtones of BMW’s 5 Series, but an American flavor (via Australia and Holden’s design team).

Where the G8 falls short is the cabin, which is stuffed with cheap-feeling plastics, not to mention the illogical control and gauge layout. The most notable problem is the placement of the bar graph-style digital oil pressure and engine temperature gauges atop the center stack in a display more suited to a navigation or driver information screen. Thankfully, the word on the street is that Pontiac will ditch these obvious add-ons for the ’09 model year and replace them with a much more useful storage compartment. And while that takes care of one major eyesore, the design team needs to beg, borrow, or steal the funds necessary to eliminate the instrument panel’s mismatched grain patterns, and move the controls for the windows and side mirrors to somewhere other than the middle of the center console. In addition, the side mirrors could use to be a bit larger and with at least one nearly horizontal surface to increase the visual area and the driver’s orientation to what is seen in the glass. Finally, Pontiac needs to put more sound deadening in the doors so they don’t sound like they came off a 1976 Toyota Corolla. The combination of these faults is enough to make any true motoring enthusiast look elsewhere.

However, credit should be given to the engineers that tuned the G8’s suspension and developed its powertrain system. Dynamically, the G8 is superb; able to handle an autocross track with ease, while still providing a surprising amount of comfort on the pot-holed roads of Metro Detroit. What really makes the G8 a blast is the 361 hp, 6L V8 engine and 6-speed automatic transmission that powers it. Its ample 385 lb.-ft. at 4,400 rpm really makes this family sedan go, but it’s the smoothness and quick response of the transmission that moves the G8 into the company of such more expensive competitors like the BMW 5 Series and Mercedes E-Class. Unfortunately, there’s another nagging problem that pulls the G8 up short, or – in this case – doesn’t: a spongy dead feeling brake pedal that left me feeling less than confident about the G8 ultimate stopping capabilities.

In short, the G8 is much better than the GTO and almost enough to make you forget there ever wan a Grand Prix or the Bonneville in Pontiac’s lineup. This is a different beast altogether. But the G8 still falls short of greatness in some fundamental areas though it’s a good attempt and a good value that with the ability to change the way people look at American family sedans and Pontiac in particular.

Vehicle as Driven:

Engine: 6-liter V8

Horsepower: 361 @ 5,300 rpm

Torque: 385 lb-ft @ 4,400 rpm

Transmission: 6-speed automatic

Wheelbase: 114.8 in.

Overall length: 196.1 in.

Height: 57.7 in.

Width: 74.8 in.

Curb Weight: 3,995 lb.

Price: $31,245