Lewis Hamilton happy 2011 season is over after Brazilian Grand Prix retirement

The McLaren driver was hit by a gearbox problem early on in the race and ended up having to retire on lap 37 after the issue became terminal.

Hamilton, who has enjoyed a season full of ups and downs, admitted he was just pleased he can now move on and start focusing on next year.

"I'm just happy the season's done," said Hamilton. "I think it's been an interesting year, and today I was giving my all.

"I feel like I enjoyed the race and it's a bit unfortunate for us and the for the team that we weren't able to get the extra points, but otherwise I enjoyed racing out there.

"I was challenging Felipe [Massa] in the end, but the gearbox problem came quite early so I was struggling with the gears."

The Briton, who finished in fifth place in the standings, said he will now relax before he focuses on getting stronger ahead of the start of next season.

"It's not really a relief," he said about the end of the season. "It's just that we've had a long, long year. I'm looking forward to a bit of down time and then just attacking next year.

"I've got lots I can improve on, but I feel it's all positive, even if we didn't have a great result today."

Hamilton said the gearbox problem had hit him early in the race, which is why he was unable to make any progress before his retirement.

"The gearbox stopped having good shifts from quite early on and so that's why every time we came out of the corners people just pulled away from me. It was a really, really slow gearshift, so it was almost like I was doing it manually myself."