Teams and spectators will pause to remember victims of the mysterious MH370 plane disappearance Sunday in a sombre start to a Malaysian Grand Prix that looks likely to be packed with incident.
Organisers will hold a minute's silence before the Formula One race for a tragedy that has deeply affected national sentiment and put a brake on ticket sales.
Drivers will wear helmet stickers reading "Pray for MH370" and the Malay-language "Doa Untuk MH370", and cars will also carry messages of support after 239 people were presumed killed in the missing jet.
"We remind ourselves that this is a huge international event, regardless of our state of mourning. The world will be on us to see how fragile or how strong (we are)," Sepang circuit CEO Razlan Razali told AFP.
The race could be high on entertainment, especially if Malaysia's torrential rain returns to cause more problems after a chaotic qualifying session on Saturday.
Mercedes' Lewis Hamilton ended up on pole position but only after qualifying was delayed for nearly an hour because of rain, and then suspended twice for crashes on the slippery track.
"It was very, very tricky for everyone," Hamilton said. "Particularly at the end, it was almost impossible to see."
The Malaysian race has twice been disrupted by rain in recent years and another deluge would be welcomed by defending world champion Sebastian Vettel as he bids to reel in front-runners Mercedes.
Three hours before the 4:00 pm (0800 GMT) start, the sky was cloudy over the Sepang circuit and weather bulletins were forecasting thunderstorms for the afternoon.
'In rain everything is possible'
"We're here to win, we know that in rain everything is possible," said Vettel, who qualified second as his Red Bull team work through their severe technical difficulties.
The reliability of the new Formula One cars, following this year's widespread rules changes, will face a test in either rain or in dry conditions, which are usually accompanied by intense heat.
Both Hamilton and Vettel retired early at the season-opener in Australia, and the Red Bull driver had battery problems in qualifying, which his team had to scramble to fix.
Hamilton's team-mate Nico Rosberg, who won in Australia, will start from third, with Ferrari's two-time world champion Fernando Alonso fourth after he was cleared of blame over a collision in qualifying.
"I'm so happy with this qualifying -- it's probably the biggest smile for a fourth position in my career," said Alonso.
Red Bull's Daniel Ricciardo, controversially stripped of second place for a fuel infringement in Australia, gets under way on the third row alongside Ferrari's Kimi Raikkonen.
But McLaren will have to fight their way into the reckoning with Kevin Magnussen starting eighth and Jenson Button 10th after technical troubles marred their qualifying efforts.
Fans will also be keen to again hear the noise -- or lack of it -- after this year's quieter, hybrid engines drew complaints from promoters and a promise to raise the volume from F1 boss Bernie Ecclestone.
"It sounds terrible on TV. The problem isn't that, the problem is for the people who are coming here and the whole atmosphere," the British billionaire told Sky Sports.