IT is no surprise that the Mazda3 has been a runaway success.

Sharing its platform architecture with the Ford Focus and Volvo S40/V50, the Mazda3 - like its kissin’ cousins - ticked all the right boxes on price, dynamics, looks and equipment.

Such has been its success locally that the Mazda3 sedan and hatch now represent about 40 per cent of local Mazda sales volume.

This year it is the second-best seller in the sub-$40,000 small car segment behind Toyota’s Corolla.

So how do you improve on success? By not changing too much and listening to feedback on what needed upgrading.

Despite the car’s strengths there were some minor annoyances with the sedan and hatch.

Mazda claims owners did not mind but we had issues with tyre, road and rear suspension noise, which took the gilt edge off the 3. We know we’re being pedants but the low-speed harshness and booming at high-revs was annoying, mostly because the car was so good in all other areas – dynamics, steering and ride.

However, Mazda’s Hiroshima engineers have been listening.

The 2007 model gains some significant improvements in noise, vibration and harshness, with extra body stiffening, sound deadening and the adoption of less noisy tyres.

The hatch and sedan’s luggage area has also been redesigned to increase practicality. In the hatch luggage space is up 40 litres to 340 litres.

There have been some modest gains in the 2.0-litre four’s fuel economy too in the Neo and Maxx, as well as the SP23, which gains a new six-speed manual and electronic throttle control.

Importantly too, dynamic stability and traction control is now available on all models.

It’s an extra $1000 on the Maxx, Maxx Sport and SP23 and is part of a safety pack on the Neo, which also includes four airbags.

Such safety additions complement the standard anti-lock brakes, anti-whiplash front headrests, dual front, side and curtain airbags on the SP23.

The steering wheel has also been redesigned to help reduce the risk of serious knee injuries in a serious frontal impact.

Visually, the range gets new bumpers, grilles, alloys and more elegant seat trims and finishes.

The SP23 wants for little with the 2.3-litre four developing the same outputs as the previous model - 115kW at 6500rpm and 203Nm at 4500rpm.

Like the Maxx and Maxx Sport, it gains cruise control as standard as well as the visual tweaks and new 17-inch alloys.

Apart from the standard six-speed, SP23 buyers can also option the five-speed Activematic auto, which now gains sequential shift and steering column buttons.

The SP23 equipment list runs to climate-control air-conditioning, steering wheel audio and cruise control switches, foglights and LED lamps on the sedan, similar to the SP23 hatch.

The 3’s dynamics, as we’ve written before, are a strong point and required little massaging. If it ain’t broke, don’t fix it.

The original SP23 steered, pointed and handled particularly well and the same can be said about the newcomer.

Minor changes to the dampers across the range have delivered a flatter ride and more stable roll control, while some tweaks to the multi-link rear suspension were designed to deliver improved grip and stability.

New steering mounting points up front are said to improve steering response and reduce understeer.

We briefly drove the SP23 over the same roads we experienced with the original back in 2004 and without a back-to-back comparison it was hard to tell how much improved the newer car was over the original.

Certainly the extra sound deadening and stiffer body have toned down the drumming noise sometimes experienced in the cabin at high revs and the wind noise certainly appeared to be lower.

The cabin felt and sounded quieter – Mazda claims up to 1.5 decibels quieter - but we may need more time behind the wheel to compare it definitively against its competitors, particularly the Holden Astra.

Fun and feel items on the SP23 include the new paddle shift buttons on the automatic. These are a welcome addition for budding Fangios.

Downchanges are accomplished via thumb buttons on the front of the steering wheel, while upchanges are easily taken care of via pressure pads behind the wheel.

Such is the SP23’s all-round balance, control and high grip threshold that it requires some ham-fisted driving before the DSC will activate.

Like the previous model, the SP23 is a superbly balanced car and, like the rest of the range, delivers a highly capable driving experience.

The SP23 has always been a safe, comfortable and predictable car to drive. Now it is also quieter.

The latest enhancements not only make it better – but harder for its key rivals.