Valtteri Bottas says he is 'mad' at himself after hitting the wall in Australian GP

Valtteri Bottas says he is "mad" at himself after he hit the wall on the exit of Turn Ten whilst on the tail of Fernando Alonso in the Australian GP - an error which probably cost the Finn a podium finish in the season opener.

However, the reversal in form was not the work of a winter, but instead part of a long-term rebuilding plan implemented at the Grove team. "We have done so much work not just over the winter, but the last 12 months," Williams revealed. "When we realised where we were last year we had to make a lot of changes across all of the business and one of the first of those was to augment the talent we have on the engineering side and the first of those was Pat [Symonds] as our Chief Technical Officer. "Obviously we brought the Mercedes engine in as well and we got Felipe Massa into our driver line-up which is great - there has been a lot of work and I hope we get reward for that this season." Kobayashi escaped punishment for the collision with Massa after the stewards decided "the incident was caused by a serious technical failure completely outside the control of the driver." Sky F1's Davidson revealed the Japanese driver told him he only had front brakes with a KERS failure the suspected cause of the first-corner collision.