Paul Atherton BBC Sport Online

The countdown to the new Formula One World Championship began in earnest on Wednesday when Toyota became the first team to launch their 2003 challenger.

The unveiling of the new TF103 car is a significant moment in Toyota's history, for 2003 is a crunch year for the Japanese car giant.

Last year - their maiden season - Toyota made a satisfactory start to their F1 career.

They took an understated approach, setting themselves no targets, and employed two drivers who ensured that no-one would be expecting too many fireworks.

Britain's Allan McNish and Finland's Mika Salo helped Toyota to a reasonable 10th place finish in the manufacturers' championship after a moderately impressive season.

We want to qualify at least one TF103 in the top 10 at all the races Toyota team boss Ove Andersson

The real difficulties lie ahead, though.

Toyota have high expectations of their time in F1, and with a reputed �150m to spend a year, have one of the biggest budgets in the sport.

Changes ahead of the 2003 season were therefore inevitable.

Both McNish and Salo were dumped at the end of last season, with Toyota instead turning to veteran Frenchman Olivier Panis and rookie Cristiano da Matta.

Panis should provide a good blend of experience and speed, while Da Matta is an exciting prospect, even if his appointment owes as much to marketing as performance.

The Brazilian romped to the title in the US-based Cart series last year, which should increase the profile of Toyota's F1 team in such a crucial marketplace in 2003.

But if Da Matta and Panis are to have the necessary impact, the TF103 will have to be up to scratch.

Toyota made a decent fist at their first F1 car - it had an impressively strong engine, but lacked the downforce needed for genuine pace.

Toyota have turned to Da Matta and Panis

Toyota chief designer Gustav Brunner hopes this problem has now been eradicated.

He said: "We have changed everything and improved every aspect of the car with the main emphasis on aerodynamics."

Toyota's F1 team will also be aware that the TF103 must reap more than the two points achieved last year - courtesy of two sixth place finishes by Salo - to justify their massive expenditure.

And comparisons with Japanese rivals Honda - who supply engines to the BAR team and finished ahead of Toyota in 2002 - will be even more pertinent.

Team boss Ove Andersson said: "In 2002 we picked up two lucky championship points.

"In 2003 our aim is to score points regularly based on our competitiveness and the new points-scoring system.

"We want to qualify at least one TF103 in the top 10 at all the races."

It is often said that it is a new team's second season in F1 that is the most difficult.

That is because while their first car is built while they are building up the team, the second has to be designed while they are racing the first - a far more complicated prospect.

The TF103 will reveal how well Toyota have coped with that challenge.