Car making is a game of leapfrog. One maker builds a new model, it is overtaken in mid-life by another maker's offering in the same segment, then maybe a third takes the podium for a while, and the brand new version of the original takes its turn again.

In the large family car segment, the Renault Laguna II and the Ford Mondeo are widely regarded as the dynamic leaders at either end of that segment, which is now effectively two subsegments, the Ford representing the bigger car end, along with, for instance, the VW Passat.

Yet, in Ireland, the biggest seller in the segment for the guts of a decade and a half has been the Toyota Avensis, which in essence hasn't changed much since it was the Carina E many years ago. Except, of course, major changes in engine technology to add to its reputation as 'the best built car in the world'.

Now, with the launch of the new Avensis, I'll stick my neck out a little. The latest car is not just a new representation of the BBCITY focus, it is arguably the best Toyota ever built.

And also, it could well turn out to be the absolutely best car in its class just now. Bar none.

Which doesn't push the previous holders of that particular title downhill ... it just means that Toyota has climbed further up a hill where the top is still shrouded in cloud.

My recent experience has been with the 1.8-litre Avensis saloon Luna specification. Not the cheapest variety, but still affordable in the class. And which will probably be the best of its own Avensis bunch.

It has real presence on the road. This new shape is as different as you could get from the previous model, and a long time overdue. It is highly distinctive, especially from the front (and I don't go along with some first colleagueial comments that it's just a copy of the Passat).

There's a slab look from the side which is partly from the high waistline, a theme which is reinforced when you look at the wagon version.

The tail-lights are strong in shape, and though you'll only notice it when you're behind one, have an intriguing effect of suggesting their are a ring of eight separate bulbs, but it is all down to the miracles of fibre-optics.

Particularly in silver, the car looks real good. Again, I suspect this will be the colour of choice for most buyers.

Inside, there's been a major upgrade in styling and materials, which combine to effect a sense of luxury quality and flair that was not, in its best instances, something we ever associated with the outgoing Avensis cars.

There's also a lot more room, as the car is bigger in almost every dimension, and the use of a strong cab-forward styling also allows extra room to be created, particularly for those in the back seat.

The Luna has titanium-look inserts where the Sols would have wood. A metallised centre stack, rather like that in the Mazda6. And ivory-coloured fabrics are also available to relieve the blackness of other trims, something which can be a put-off to some owners.

I particularly liked the yellow figures on the Optitron instruments, which were clear both night and day and were almost as easy to read as would blue be to these somewhat aged eyes.

Small thing: in many cars, a centre armrest/cubby can get in the way of the left elbow when changing gear. The one in the new Avensis is perfectly placed and sized to act nicely as that armrest, but never once made itself awkward.

Big thing: the seats are exemplars of comfort and support, better than those in a Mercedes I've recently driven. On a long journey, I never even thought of them, which says its own message.

But biggest thing of all: the silence is golden. This is a car where much has been done to give Lexus-like environment, and indeed it could well pass for a Lexus with a rebadge (as does the current Camry in the US, with extra trimmings, of course ... and they DID launch it as a Lexus first).

Only a gutsy revving high of the VVT-i engine will intrude, and that same engine works so well in easy-going mode that no one in their right minds would bother doing that much.

Indeed, it was the easy smoothness of the drive, on a variety of roads from very good through indifferent to downright bad, that came to be the outstanding impression of the new Avensis.

It has moved out the boundaries in its segment. It has, particularly in refinement, moved on the image of the Japanese big car as being more than something reliable but not necessarily inspired. It has - to use that much hackneyed phrase - 'Europeanised' another offering from the Pacific Rim.

And it is built in Europe. To a standard that Toyota in Japan will be importing some of them for their own market there.

This time, it is Toyota's turn to be at the front of the leapfrogging. The others will catch up, and in the trying, it is where we buyers of cars will benefit.