Five things we learned after Lewis Hamilton led a Mercedes one-two at the Chinese Grand Prix in Shanghai:
What's sticky and stinks? Red Bull's year so far
Three races, two retirements and just fifth in the constructors' standings: the 2015 statistics make grim reading for Red Bull and engine-supplier Renault, who once swept all before them in F1.
With Red Bull's owner, energy drink tycoon Dietrich Mateschitz, reiterating a threat to quit the sport, his team and Renault need to work overtime to lift the storm clouds. Team principal Christian Horner was blunt about Red Bull's predicament. "It's a shitty position to be, but we've just got to engineer our way out of it," he said, according to reports.
Rosberg is well and truly rattled
Nico Rosberg has the look of a champion when things are going his way, but it's a very different matter when he finds himself behind his Mercedes team-mate Lewis Hamilton. First he snapped at mechanics when Hamilton pipped him for pole, and then he accused the Briton of deliberately driving slowly and jeopardising Mercedes' one-two finish in Sunday's race.
If Hamilton was driving slowly one solution might have been to overtake him, but regardless of the merits of his argument, Rosberg's petulant outburst showed he has very much lost his cool.
The 29-year-old German also looked rattled at the last race in Malaysia, where he vehemently denied intentionally slowing down Hamilton in qualifying. Currently third in the standings, Rosberg will need to keep his emotions in check if he wants to challenge for the world title.
Ferrari will be title contenders - in 2016
Ferrari gave Mercedes a scare when Sebastian Vettel won the Malaysian Grand Prix, but another superlative one-two in China shows the Silver Arrows are a shoo-in for the drivers' and constructors' championships, even with only three races gone.
Away from Malaysia's extreme heat, and in a more predictable race, Mercedes never looked threatened in Shanghai. However, the Ferraris had enough pace to show they will at least keep Mercedes honest this year, and are likely to be in line for a genuine title tilt in 2016.
It's not easy to be a marshal
The marshals had a tough week and inadvertently found themselves at the centre of the attention when trying to remove Max Verstappen's smoking Toro Rosso from the start-finish straight.
With just two laps remaining, track hands were slow to reach the scene and ironic cheers erupted from the grandstand as they laboriously pushed it, repeatedly getting the steering wrong and having to back up, to the safety of the pit lane.
Security was also in the spotlight during practice on Friday, when a "crazed" track invader ran across the tarmac between two speeding cars and clambered into the pit lane, asking to drive a Ferrari.
Maldonado can't get out of reverse
Venezuela's Pastor Maldonado was already a figure of fun for his many mishaps, and an unlucky run-in with Jenson Button did not help matters on Sunday. The Lotus driver, variously nicknamed "Crashtor" and "Faildonado", was headed for his first finish of the season when he was shunted from behind and had to retire on lap 50.
Scant consolation for Maldonado, the subject of a website: http://hasmaldonadocrashedtoday.com/, that Button was punished for the incident. Maldonado, who earlier overshot the pit lane and had to be pushed back on track by marshals, now has three DNFs (did not finish) in three races, putting him firmly on course to eclipse his personal record of six, set in 2011 and unhappily equalled last year.