Jenson Button said his McLaren-Honda's handling inthe Spanish Grand Prix was one of the most "scary" experiences of his Formula 1 career.
A race that the McLaren drivers thought might bring their first points of 2015 ended with Fernando Alonso retiring with brake problems and Button finishing a distant 16th.
"The first 30-odd laps were the scariest 30 laps of my life," said Button.
"The rear just wasn't there. Any time I touched the throttle at any speed, the rear was gone. It just wasn't normal.
"The rear felt like it wasn't connected to the front. It felt like every gust of wind had a massive snap.
"It was pretty horrific for the first half of the race. Switch changes and new tyres at the end helped a bit."
Button was not sure whether the handling dramas were a set-up problem or mechanical issue.
"After today I don't think I expect points at all this year, but hopefully today was an off-day. It didn't feel right," he said.
"The weekend has been reasonably good for us and I've been happy with the way the car's been, but it was like flicking a switch in the race."
Alonso ran as high as seventh on an alternative strategy, but had to retire after his brakes failed.
ALONSO 'LUCKY' IN PIT DRAMA
As he tried to bring the car back to the garage to retire, Alonso overshot his pitbox, with crew members having to jump out of the way as the car hit the front jack.
"It was scary. No brakes for the whole in-lap, and for the pitstop even less," Alonso said.
"One lap before, I missed the first corner, and I was careful, but they were deteriorating even more, and at the pitstop I didn't have any brakes.
"It was scary for the guys but luckily we didn't hurt anyone and they were very fast on the reactions."
He remained convinced that points were within reach had he managed to finish.
"A two-stop strategy seemed to work better for us this weekend," Alonso said.
"The race was going more or less as expected, so I think P9 or P10 was possible today."