Feb.6 (GMM) Polish grand prix driver Robert Kubica says BMW-Sauber is getting to the bottom of the early handling problems experienced with the team's new car for 2008.

The 23-year-old's veteran German teammate, Nick Heidfeld, revealed recently that despite hopes that the F1.08 could net BMW's maiden victory this year, the car had a tough birth on the winter test tracks.

Kubica acknowledges Heidfeld's concerns but says the Swiss based team has made progress since then.

"We have sorted out some of the problems and made very promising progress," he told F1's official website.

"We introduced some new mechanical parts and also worked on the aerodynamics, which clearly improved the car. In Poland we say that 'it's not important how you start, it's important how you finish', so I really am convinced we are doing a good job," Kubica added.

He also insists that it is difficult to analyse formula one teams' relative performances on the basis of pre-season test lap times.

"At this stage ... we are not looking at the other teams too much," Kubica said.

"It's quite normal that everybody only shows their full potential at the start of the season in Australia," he added.