The flurry of launches, spurred by stiffer safety rules, is expected to breathe new life into a stalled sector that comprises nearly one-fourth of vehicle sales in Japan, the world's second-largest market.

But despite the face-lift, analysts were wary of whether this peculiar segment, sustained by years of preferential tax treatment, could survive in the longer term.

"The tax advantages are likely to start thinning out," said Kunihiko Shiohara, analyst for ING Baring Securities. "The future prospects are not that bright."

For the near term, however, analysts expected good results from next week's product launches.

Shiohara predicted a sharp rebound in minicar sales in the second half of the fiscal year to next March, offsetting a slump in the first half to bring two percent growth for the whole year.

Daiwa Institute of Research analyst Masato Ogasawara and Warburg Dillon Read analyst Peter Boardman both forecast flat sales for the year, although this would be an improvement from the 5.5 per cent year-on-year decline for the first five months of the fiscal year.

Boardman issued a buy recommendation for Suzuki Motor Corp, Japan's top minivehicle maker with one-third of the market, due in part to prospects for domestic minicar sales.Such optimism was no small accomplishment for the minicarmakers.

The new safety standards, in effect from Thursday, also included an easing of size restrictions, which rose by 10 CM in length to 3.4 metres (about 11 feet) and increased eight CM in width to 1.48 metres. But maximum engine displacement remained a tiny 660 cc.This led many industry observers to predict prices would go up while fuel efficiency and engine performance declined, scaring off many price-sensitive minicar buyers.

But now it appears those fears were largelyunfounded.Minicar makers like Honda Motor Co and Fuji Heavy Industries Ltd have said their new minis will offer the same crash test performance levels as their bigger models.

And analysts said lighter materials and improved engine designs would help maintain fuel efficiency and performance levels, while platform sharing and other cost-cutting measures would help limit price increases to about five or 10 per cent.

The minivehicle makers' expertise in making small cars cheaply has not escaped the attention of bigger automakers. Earlier this month General Motors Corp said it would become Suzuki's leading shareholder and that the two would jointly develop small, inexpensive cars for emerging markets.Toyota Motor Corp also recently completed a buyout of Daihatsu Motor Co, a long-time Toyota affiliate and Japan's second-biggest minicar maker.

Despite the near-term optimism, however, analysts wondered whether the pitter-patter of little pistons might eventually disappear from Japanese roads, as tax advantagescome under review and a slew of better-performing cars with 1.0 litre to 1.3 litre engines, known in Japan as "litre cars", hit showrooms.

ING Barings' Shiohara calculates that a Suzuki Alto minicar with a sticker price 10 per cent below a 1.3-litre Toyota Starlet becomes 25 per cent cheaper than the Toyota when tax and insurance payments for the first year are added in.Many of Japan's automotive tax and insurance charges are based on engine displacement.