Lewis Hamilton declared his Mercedes car to be "getting worse" and dismissed any hope it will improve before next year after struggling in Friday's practice for this weekend's Canadian Grand Prix.
The seven-time world champion, who claimed his maiden Formula One victory at the Circuit Gilles Villeneuve in 2007 and has triumphed a record seven times at the track, finished a lowly 13th in second practice, AFP said.
He admitted that the Mercedes he has struggled with this season is "here for the year" and unlikely to change or be improved sufficiently to bring an upturn in form or results.
Blighted by performance problems, notably with "porpoising" and bouncing, the team had chosen to try some radical set-up ideas in a bid to solve their problems.
"The car is getting worse the more we do to it," said Hamilton.
"It's pretty much like every Friday for us – trying lots of things, including an experimental floor on my side, which didn't work.
"Nothing we do to this car seems to work. We were going in different ways but nothing works. For me it was a disaster.
"We keep working on it, but it is what it is and I think this is the car for the year so we just have to tough it out and work hard on building a better car for next year."
Hamilton said that he and team-mate George Russell, who was seventh fastest on Friday, had gone in opposite directions with radical set-up proposals to improve performance, notably the "porpoising" that has left them both with acute back pain this season.
The team's chief technical officer James Allison was at the Circuit Gilles Villeneuve on Friday to help Mercedes find a solution to their problems.
Hamilton laughed as he described the experience of driving his car as it bounced, jumped and moved around on the track.
In the closing minutes, with a new floor fitted, he told the team "this car is now undriveable".
Hamilton said also that he felt relieved to have completed the day without more serious physical concerns after suffering acute back problems last Sunday in Baku.