Audi knows a thing or two about mid-sized family cars with a prestigious feel, compact executive models like this fourth generation A4, launched in 2008 and codenamed 'B8' in Audi-speak.

It was a car significantly bigger and more sophisticated than any the brand had previously had in this segment and a big success. By late 2011 though, Audi could see that rivals had this model's measure, with a substantially improved Mercedes C-Class on sale and a frighteningly good all-new sixth generation BMW 3 Series just about to hit the showrooms.

That explained the need for the heavily revised A4 we're looking at here as a used buy, a car launched in the early Spring of 2012.

With this model, we still had the basic 2008 design, but the development team had taken it and improved just about everything possible without creating an all-new car.

Hence the arrival of an A4 that was smarter, better-equipped, safer, better to drive and more-fuel efficient.

An A4 fully ready to square up against the best its rivals had to give.

An A4 with an even bigger dose of vorsprung durch teknic.

It lasted until the arrival of the fifth generation version n the Autumn of 2015.

Aesthetic excess isn't a very Audi trait and it's certainly not much in evidence here.

There were no sheet metal changes made in the 2012 facelift: just mild cosmetic updates to a front end that now featured a set of wedgy A6-style headlamps positioned either side of a smarter single-frame grille and above a re-styled bumper and revised air intakes.

Move past what'll likely be a smarter set of alloy wheels to the rear and you'll find revised taillights with optional LED brilliance that sit above a sleeker bumper and re-styled rear diffuser. But, as ever, it's the cabin that'll really sell this car, as beautifully finished as ever, everything clear and elegant.

With this improved MK4 model, there are revised steering wheel designs, beefier column stalks, clearer white-illuminated instrumentation displays, neat chrome detailing, updated buttons and smarter upholstery.

The MMI infotainment system that most new buyers paid extra for was also easier to use, with fewer buttons and more logical menus (you could at last put a 7-digit postcode into the sat nav).

Through it, A4 buyers could access a whole raft of online options, everything from Google Earth mapping to in-car internet access. In the rear, as ever with this class of car, it's comfortable for two, but something of a squash for three adults, with the unfortunate occupant in the middle having to splay his or her legs either side of a large transmission tunnel, despite the fact that this car is front wheel drive.

It'll be fine for three children though.

Out back, there's a 490-litre boot that's bigger than that of a BMW 3 Series or a Mercedes C-Class from this era.

Split-folding rear seats extend it, in the case of the saloon, to 962-litres.

Of course, if you are going to be carry bulkier stuff on a regular basis, you'll want to consider the Avant estate bodystyle, which offers a 490-litre boot extendable to as much as 1430-litres if you flatten the rear bench.

Reliability isn't generally an issue for the A4.

Many models will have done high mileages in the hands of overworked sales reps but that shouldn't necessarily put you off.

Look for a fully stamped-up service history and keep an eye out for uneven tyre wear on the more powerful models. The most common problem with A4s occurs in some area of the electrical components; e.g., the brake lights stay on, the trip display burns out in a few spots, or the power window motor might burn out.

These repairs are not very expensive, although having to replace a bad circuit for the taillights would be pricey.

We'd steer clear of an A4 with trip display problems too, because replacing that screen is expensive. In the highly unlikely event that some sort of engine problem presents itself, it would be expensive to repair because of the quality of the parts.

On an older very high mileage car, you should have the timing belt replaced if it hasn't been already; should it not be replaced and it breaks, you expect a hefty bill and the engine compartment would be in bad shape if this were to happen.

Have the brakes checked as well; the car in question might need new pads/rotors.

(approx based on a 2012 A4 1.8 TFSI) A clutch assembly kit will be around £250 and an exhaust system (without catalyst) will be about £300.

An alternator should be close to £150 and a radiator around £170.

Front brake pads are around £75, rear brake pads will be £50.

Get behind the wheel and even blindfolded, you could probably guess you were in an Audi.

The great driving position, the smell of quality, the way all the controls are so beautifully damped: all are Ingolstadt giveaways.

But when this modern generation A4 was first introduced in 2008, the company knew it had to go further.

Class leadership would require a conscious effort to reward owners as much out on the road as in the driveway.

The engineers acknowledged that this car's front-driven layout might never reward an enthusiast in quite the same way as a rival rear-driven BMW 3 series.

But they were convinced that it could be made to feel almost as good. To prove the point, they took a completely clean-sheet approach in creating the original version of this car, developing an entirely new MDS platform that saw the engine moved way back from its usual position just in front of the front axle to a point behind it.

Since the engine is the heaviest part of any car, that change was pretty significant, distributing this Audi's mass more uniformally across both axles.

That improved handling response, while the longer wheelbase necessary to facilitate the change enhanced the ride quality. Of course, whatever you do, you can't change the laws of physics.

A BMW 3 Series still feels more responsive if you're out to rival Lewis Hamilton on your favourite backroad.

But the differences to this post-2012 MK4 model A4 aren't great and the suppler ride you get with this Audi (providing you don't choose a car with huge wheels and stiff suspension) will be preferable for many.

Some original buyers tried to improve things further by specifying a 'chassis with damper control' set-up, allowing them to match the ride to road and mood. Others tried to make this even more of a driver's car by specifying their A4 with the option of quattro four-wheel drive, something that our wintry climate made tempting.

Normally, this system distributes the engine's power primarily to the rear but if necessary, can redistribute torque towards the front at lightning speed.

Opt for a car fitted with the Sport differential that was available on the top 3.0 TDI and S4 models and torque can even be distributed from side to side at the rear, firing you from corner to corner. So far so good.

What let the side down a bit though on the original version of this car was the steering and as a result, this revised version got an all-new hi-tech electromechanical set-up which was supposed to enhance driver feedback, though that's still not this car's strongest suit.

Some original buyers tried to improve things by paying extra for 'dynamic steering'.

Others ignored this but did choose to pay the extra for Audi's optional 'Drive Select' system which makes a big difference to the driving experience.

It alters steering feel along with engine management, throttle response, the change parameters of the auto gearbox response - even the air conditioning - in line with your choice of 'comfort', 'auto', 'dynamic' or even 'efficiency' modes.

It'll also tweak the ride in tune with your chosen setting if you paid for the 'chassis with damper control' set-up. Under the bonnet, if you're an enthusiastic driver, less is probably more.

With less weight to carry around, lower-order 2WD petrol and diesel models feel more agile and more responsive than their pokier 3.0-litre stablemates and we prefer the 6-speed manual transmission to the auto-only set-up you're limited to on pricier models.

In the TFSI petrol line-up, it's best to ignore the entry-level 120PS 1.8-litre unit and begin your search with the engine Audi spent most time on in this revised range, the 170PS 1.8 TFSI.

Here lighter, more efficient, pokier and torquier, it powers this car to sixty in 8.1s on the way to 143mph. Beyond that, there's the venerable 211PS 2.0-litre unit from the Golf GTI, this offered with two or four wheel drive.

For us, a 2.0 TFSI A4 capable of sixty in just 6.9s on the way to 149mph is pretty much the perfect package.

The 2.0-litre TDI diesels also offer plenty of performance: lower-powered 136 and 143PS versions make sixty in around 9s on the way to around 130mph.

Pokier variants with 163PS or 177PS, manage the sixty sprint in about 8s on the way to around 140mph. That only leaves the 3.0-litre models, two of them diesel-powered.

3.0 TDI buyers choose between a 204PS variant with two wheel drive and 8-speed Multitronic auto transmission, a surprisingly efficient package.

Or a tempting 245PS 3.0 TDI quattro model with 7-speed s tronic auto transmission - a car that's really very quick indeed, sixty from rest occupying just 6.1s on the way to an artificially limited 155mph maximum.

Or at least you'll think it is until you try the flagship S4 quattro model, powered by a 333PS supercharged 3.0TFSI six cylinder petrol unit as quick as any V8.

Here, sixty is just 5.0s away from rest.

There are plenty of reasons behind the MK4 model A4's success.

It's a spacious, classy car that's very composed to drive and is fully conversant with the kind of hi-tech design and faultless cabin quality that its target junior executive market likes to expect.

As a result it always stacked up in the showroom just as well as it did on the balance sheet, with running cost returns that with most engines made it a company accountant's go-to choice. These virtues didn't change in this fully revised post-2012 facelifted version.

But they were embellished, with the result that even more than before, this A4 feels like a car that's been lovingly and very carefully considered.

The depth of engineering and the thought that's gone into the tiniest details make it a sound used buy and combine to further enhance the warm fuzzy feeling that's charmed Audi customers for years.

If you're one of those people, then you'll like this car very much.

And even if you're not, you'll find it hard not to be impressed by way it systematically ticks almost every box on the compact executive market wish list.

It's very thorough.

And very Audi.