Toto Wolff suggested Mercedes made "all the mistakes we can make" during a disappointing Abu Dhabi season finale.
The Silver Arrows had its optimism raised with a first victory of the season in Brazil only for past issues to reemerge at Yas Marina.
Poor drag efficiency and porpoising left Lewis Hamilton and George Russell trailing in qualifying, securing only fifth and sixth on the grid, whilst Red Bull and Ferrari were both able to hold Mercedes at arm's length in the race.
To make matters worse, Mercedes suffered a first mechanical failure of the season when Hamilton retired three laps from the end with a suspected hydraulics issue.
"That was really not good, all the mistakes we can make," Wolff told Sky Sports F1.
"The car was not at the pace it should have been, third quickest and one breaking down and the other one running out of tyres.
"We knew that Abu Dhabi was going to be difficult for the car, certainly the correlation is good."
W13 to serve as Mercedes reminder
Hamilton had said before the weekend that he could not wait to leave the W13 behind after the post-season test in Abu Dhabi next week.
On what would happen to the machine in retirement, Wolff suggested: "We are going to put this car in reception in Brackley and Brixworth to remind us every single day how difficult it can be.
"Thank you, everyone. This is a character-building season. Not a blip for a race but a full season.
"But you kept pushing so hard, the engine went really well and proud of what we achieved there.
"On the chassis side, there were more bad moments than good ones but the good ones were spectacular, made us feel how good it can be.
"Now we are just pushing forward for next year, it is rough, bad and it is ok to feel like this but next year, we are back."