World champions Red Bull want to erase a blank spot on their Formula One world map with a first victory at the Canadian Grand Prix but it remains to be seen how the car fares after they were ordered to close holes in its floor.

The ruling body FIA has deemed the holes in the floor illegal as Red Bull pleaded in vain that they complied with regulations and gave them no aerodynamic advantage.

Red Bull are the only team with two season victories, from drivers’ champion Sebastian Vettel in Bahrain and Mark Webber at the last race in Monaco, but they are yet to top a podium on the Circuit Gilles Villeneuve.

The 2012 season has been unpredictable with six different winners in as many races for an F1 record, and the tally may well rise to seven given that McLaren’s Lewis Hamilton is yet to win this season, and Michael Schumacher’s Mercedes and the Lotus of Kimi Raikkonen could also be good enough for the top.

“So many things can happen. It is very difficult to predict,” Vettel said.

As a result, the championship is very tight, with Ferrari’s Fernando Alonso leading the way on 76 points, three ahead of Vettel and Webber. Hamilton has 63, Mercedes’ Nico Rosberg 59, Raikkonen 51 and Jenson Button 45 in the second McLaren.

Button has excellent memories of Canada as twelve months ago he won from last place at the halfway mark, roaring past Vettel in the last lap of a race stopped for two hours because of rain.

“Obviously, returning to Montreal will be an extremely proud and happy moment for me,” Button said.

“My win there last year was one of those rare occasions when everything just came right -- it’s still hard to believe that I was running in last place past half-distance and yet still managed to come through and take victory on the final lap. The memories of that win will always be with me.” Button has earned just two points in the last three races and quickly needs a turnaround, a fact that also applies to the veteran Schumacher who has the same amount of points from all six events owing to misfortune and mishaps.

Mercedes have been competitive, with Rosberg winning in China and Schumacher posting the fastest time in Monaco qualifying although a grid penalty cost him pole position for the race from which he had to retire with technical problems.

“The race in Montreal is usually action-packed, like we saw last year. The characteristics of the circuit should suit us, and we are counting on our car performing well there,” Schumacher said.

Schumacher has seven career victories in Montreal while McLaren have won four of the last six editions and now seek a third straight after Hamilton’s second win in 2010 and Button’s heroics last year.

Like Button, Hamilton has great memories of the track as he claimed his first career victory there in 2007.

The action starts Friday with two practice sessions on the 4.361km course, qualifying is on Saturday and the 70-lap race at 1800 GMT on Sunday.

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