The Icarus syndrome burned Renault. And by launching the commercial dud that is the Phaeton, Volkswagen’s pride suffered, too. For mainstream car brands, the higher their aspirations, the more devastating the fall can be.

And yet the mass market brands can’t resist periodic pops at the German premium brands’ luxury car market-stranglehold.

Some seven years after the Scorpio bowed out, Ford believes it has a successful formula for a new flagship – the production version of the SAV concept car. In June, the finished car enters showrooms, wearing the S-Max badge.

As the proposed name suggests, the car is a big brother to the C-Max mini-MPV. It’s a shrunken Galaxy, but with sleeker lines and a 5+2 seating arrangement. Sources are talking up its sporty dynamics, backed by meaty engines. The launch line up will feature 144bhp 2.0-litre four and 220bhp 2.5-litre fivepot petrols, and the 134bhp 1.8-litre and 175bhp 2.0-litre TDCi diesels.

Could it suffer the same fate as the Avantime? The Ford is certainly less avantgarde. And by sharing a chassis with new Galaxy and Mondeo, Ford hasn’t bet the farm on the S-Max and can massage production according to demand.

Vauxhall will be scrutinising its arch-rival’s performance. For GM has finally worked out what to do with 2003’s gorgeous Insignia concept: use its design to shape the next-generation Signum. And you guessed it: this new flagship will go head-to-head with the S-Max.

GM bosses admit that they didn’t quite get the Signum right. The flaw? A nose identical to the workmanlike Vectra, a car as aspirational as Poundstretcher. But they believe enough in the concept of a versatile, luxurious hatchback to have a second stab at the formula.

The new car will have to follow the new Vectra, which isn’t due until 2008. Vauxhall will use a stretched version of its Epsilon II platform, having ruled out a rear-wheel drive Holden base.

Two versions are planned. The standard version has a rear bench that switches between two armchairs and three perches, Signum-style. An XXL version has a longer rear overhang to accommodate two foldaway extra seats.

This flagship may even get four-wheel drive, which GM is plumbing into the next-generation Epsilon platform to help Saab keep up with the increasingly powerful Germans. Likely engines include V6 turbo petrol and 200bhp-plus diesels.

So will the sun shine on Vauxhall, or will it get its fingers burned? We must wait until 2009.