That bend, somewhere north of Gothenburg, was the first of a series of forest-bound twists, and I was in the 9-3 Aero: 210bhp, firm and low-riding suspension, flared-out lower body panels, oval exhaust pipe. Intriguing. I turned the steering wheel a little, the Saab moved instantly, obediently, cleanly. This was good. Turn a little more, feel the response quicken; there's no understeer here. The tail was clearly helping the process, almost as if the rear wheels were steering the opposite way to the fronts, helping to guide the Saab along an invisible rail-curve.

Which is exactly what was happening. Saab's new 'ReAxs' rear suspension applies about a hundredth of a degree of counter-steer as it compresses or extends, a simple trick that bestows the car with real agility. The new 9-3 is a real driving machine and banishes bad memories of the old 9-3 Viggen.

That the new 9-3's wide-track platform is broadly that of the new Vectra doesn't matter. Saab contributed just as much as Vauxhall/Opel to its genesis, the 9-3's wheelbase is shorter and its multi-link rear suspension geometry different, even if the basic layout is similar. The 9-3 feels credibly Saabish in other ways, too, even in the sound of its turbocharged engines.

Which is a surprise given that they, too, share GM architecture. The head and the block are those of the all-aluminium, 2.2-litre, balancer-shaft-equipped L850 unit found in Vectras, Astras and the VX220, but all the other bits are Saab-specific and the engine, like the transmission, is Swedish-built. All three petrol engines have a 2-litre capacity - achieved by shortening the stroke - and that even includes the entry-level 150bhp unit, bizarrely badged 1.8t to match same-named Audis. The other outputs are 175bhp and, for the six-speed Aero, 210bhp.

But what happened to the 9-3's former USP, its hatchback? Simple; premium buyers prefer saloons. Trouble is, some distinctiveness is lost. The nose, rising waistline, windscreen shape, blacked-out B-pillar, side crease and angled tail-light edges are all typically Saab, but the 9-3's identity is too low key. It should have a concave rear window/boot line, like the 9-5 and nearly every Saab since 1967's 99. That said, there are some visually more interesting variants in the pipeline. First a convertible, then an estate, then three and five-door quasi-coupes based on the 9X and 9-3X concepts.

Inside, the 9-3 is unmistakably Saab with clear ergonomics, joystick air-vents, a Black Panel function and clean curves. Most surfaces are padded or soft-touch painted; the remaining hard plastics weren't of great quality in our pre-production test cars but that will be fixed by September's on-sale date - to 9-5 standard or better, which will be fine.

Three clevernesses stand out. The handbrake looks like part of the centre console's edging until you realise it moves; the key still engages in a slot by the gearlever but now triggers a remote electric steering lock; and the cupholder trumps even the 9-5's gyroscope-look item with a double reverse flip into two butterfly-like wings. It's surely a favourite for the next Euro NCUP award.

As to how the 9-3 goes; the Aero is naturally the most rapid and its boost builds quickly, but you wonder if there's quite as much power as claimed until you look at the speedo. That's a measure of the engine's refinement, and the low noise from other sources. It rides well, too, despite its shallow sidewalls, and torque-steer is almost entirely absent - possibly a first for a top-potency Saab.

Yet the 175bhp 2.0t is, in some ways, the more pleasing. Its delivery is more progressive and the ride more supple, yet that agility is still there and outright pace isn't much less. All petrol engines (there's also a carry-over 2.2-litre turbodiesel) have drive-by-wire throttles which open a little more pre-boost to get the turbo spinning, and which sharpen their response if they detect press-on driving.

These new 9-3s are good cars. As in the Jaguar X-type, you do get a slight feeling of mass-market parts hidden behind an aristocratic veneer, but the Saab carries it off better and feels fabulously solid. Crucially, it's more fun than an A4 and as interactive as a 3-series, while costing less than both. Job done, then.