Images from Friday's opening stages of the Wales GB Rally. In pictures

Meanwhile, rally officials have welcomed the Welsh Assembly Government's announcement that the event would stay in Wales until 2011.

British governing body, the MSA, said the Wales Rally GB had gone from "strength to strength".

This weekend's race started with stages through the Brechfa forest and ends in Cardiff on Sunday.

The five-year extension is estimated to be worth �40m to the Welsh economy

MSA chairman John Grant said: "There are in fact very few locations in Great Britain that can offer what Wales can.

"The rally enjoys the support of the capital city and has developed a special relationship with Cardiff City Council and in terms of the sport, the environment is superb with those fantastic forests through which most of the rally runs."

Andrew Davies, the economic development and transport minister, made the sponsorship announcement during a conference at the rally centre near Swansea on Thursday.

The eve of race "ceremonial start" took place outside the Millennium Stadium on Thursday but drivers will return there on Saturday evening.

For the first time in the World Rally Championships, a stage is to be held indoors.

WALES RALLY GB TIMETABLE Friday 16: Six forest stages in west and south Wales, 0758 BST from Brechfa to Rheola Saturday 17: Seven forest stages in mid and south Wales, 1028 BST from Crychan and spectator stage in the stadium Sunday 18: Four forest stages in south Wales, 0758 BST from Resolven to Margam; finish in Cardiff

Drivers will race round a 0.62-mile figure-of-eight track specially constructed in the Millennium Stadium.

Several young Welsh drivers are competing in the rally - many of them as amateurs.

Stuart Jones, 20, said he was excited about competing on his home turf in his first big race.

The young driver, from Guildfield, Powys said: "It's great, it's brilliant. Even though it has been hammering it down, it's a great atmosphere.

"It's such a big event compared to what we're used to."

Jones - who has been rally driving for three and a half years and recently won a place on the GB Rally elite scheme for young drivers - is competing in Group N, driving a Mitsubishi Lancer.

Friday morning will be a big moment for 20-year-old Kevin Davies, too.

Finnish driver Marcus Gronholm in his Peugeot during the Brechfa forest stage of the rally on Friday. Enlarge Image

Davies, from Llanfihangel Ar Arth, Carmarthenshire, has only been rally racing for 12 months.

Despite his relative inexperience, he told the BBC News website he was relishing the prospect of taking part in such a big event.

"It's been a brilliant year. At the beginning of the year this was not the plan. I hadn't dreamed it," he said.

There will be several road closures in Wales during the event.

Police said they had worked closely with the rally organisers and the mid and south Wales Safety Camera Partnership to ensure there was plenty of time for spectators to travel between stages.

Event Commander Superintendent Phil Davies urged people going to watch the rally to drive responsibly, adding that speeding offences had dropped significantly since 2002 and police hoped to build on that this year.

Live: Wales Rally GB

Mr Davies also advised spectators to park legally and respect the local communities they were driving though.

Despite the complexity of managing the event, the superintendent said he welcomed the announcement that the UK leg of the championship would remain in Wales for another five years.

"It's excellent news for the local communities because we appreciate the benefits it brings," he said.

Another young Welsh hopeful, Leon Pesticcio, said he was raring to get to the start line in his Suzuki Ignis.