IT has been four long years in the making, but the latest Audi A4 line-up has just been unleashed and it's bigger and better than ever.

Almost every single part on the outside of the car has been changed and the interior has undergone a make-over too. There are mild hybrid powertrains and a choice of seven - four diesel and three petrol - engines to choose from.

And, of course, customers can opt for the saloon body styling or Avant estate, along with a selection of trims called Technik, Sport, S line, Black edition and a luxurious Vorsprung option.

We selected the A4 Avant in S-line trim level powered by a 2.0-litre diesel 40 TDI quattro engine delivering 190ps and 400Nm of torque, mated to a seven-speed S-tronic dual clutch transmission.

Costing £37,635 - increased to £42,535 with options - this model could complete the 0-62mph dash in 7.6 seconds and maxed out at 143mph. And according to official figures,it could deliver combined fuel efficiency of 44.1mpg with carbon emissions of 140g/km.

Audi has really upped the ante with the new A4 Avant S line. It boasts a sportier, more dynamic front end thanks to new LED headlights, front bumpers, air inlets, side sections, wings, doors, tailpipe trims and rear light clusters. In fact, only the boot lid, bonnet and roof remain unchanged.

It's a car guaranteed to draw attention wherever it goes. Upon viewing the car, one neighbour actually mentioned that he generally disliked estate cars, but was very fond of the styling of the new Audi Avant.

Move inside and the designers have been busy there too. The traditional rotary click dial used to navigate the multimedia systems has been dumped in favour of a new infotainment system with larger touchscreen. And the excellent Audi Virtual Cockpit also becomes a standard feature.

Creature comforts include afull navigation system, heated front seats, a wireless phone charger, deluxe three-zone climate control, full smartphone connectivity, reversing camera and plenty more besides. And when you factor in some fine leather and Alcantara upholstery, plus lots of soft touch surfaces, the A4 Avant is quite the class act.

When it comes to performance, the car is an absolute dream to drive as it eats up the motorway miles for fun. It almost seems to glide across the Tarmac and willingly displays its more dynamic side when faced with twisting country lanes. The road holding is ultra grippy and tight bends can be attacked with confidence.

The acceleration through the seven-speed automatic gearbox is very smooth and there are paddles to take more control if the mood takes you.

It's a car that feelsbeautifully balanced as it fires along the faster B roads and there are drive modes called Efficiency, Comfort, Auto, Dynamic and Individual that alter the way the vehicle reacts. Comfort is ideal for everyday use, but Dynamic is always worth exploring for the fun factor.

The A4 Avant stretches 4.7 metres in length, but proved easy to manoeuvre in busy town centres and parking is simplified thanks to the reversing camera and parking sensors.

Obviously, someone opting for the estate body-styling is going to require lots of boot space and the A4 Avant doesn't disappoint with a capacity ranging from495 litres to 1,495 litres with the rear seats dropped flat.

Back seat passengers are treated to ample leg space provided the front seats are not pushed back too far, but any middle seat occupant will find their legs straddling a rather large central tunnel.

Audi has a strong reputation for developing safe cars and the A4 Avant is packed with kit to protect occupants and help prevent accidents from happening in the first place.

Standard features on the car includedhigh beam assist, anti-lock brakes, cruise control with speed limiter, Isofix fixtures, a full suite of airbags and Audi's quattro AWD system to help keep you moving in more adverse driving conditions.

Our car also had aDriver Assistance Tour Pack that added £1,250 to the cost and introduced adaptive cruise assist with stop & go and traffic jam assist, traffic sign recognition, turn assist and active lane assist, collision avoidance and Audi pre-sense front that detects pedestrians or vehicles ahead and then warns the driver. If the warnings are ignored, the car will automatically take the necessary action to reduce speed.