LONDON, England - Mercedes gave its new Formula 1 car a track debut away from prying eyes on Thursday amid lingering suspicions that the late arrival meant the team had something to hide from copycat rivals.The team said Michael Schumacher and Nico Rosberg each did 50km on the Silverstone circuit for what was officially a private filming day before the launch of the W03 at the second pre-season test in Barcelona next week.ALWAYS POSSIBLEGerman media have speculated that the car, which has a stepped nose like all the others except McLaren, has been held back to give rivals less time to crack its secrets before the season starts in Australia on March 18.Adrian Newey, multiple title-winning designer for current champion team Red Bull, told Reuters that was always possible."I was told by the German news meda, whether this is true or not, that the car was ready to run at the last test but they chose not to and why would that be?," he asked before being inducted into the Motor Sport magazine Hall of Fame at an event in London."I said I've no idea but why you might choose to do that would be if you had some feature on your car which you think is a big benefit and which is relatively easily copied. I'm not saying that is the reason, but it's possible .Mercedes, run by former Brawn GP principal and ex-Ferrari technical director Ross Brawn, has said it decided to launch the car later than others to give itself maximum time for development.Red Bull, Ferrari and McLaren each tested their new cars in Jerez last week. Apart from Mercedes, only Marussia (formerly Virgin) and HRT have yet to take the wraps off their 2012 machines.SIX WEEKSNewey said it would take about six weeks to evaluate properly a development on a rival car and get it to the point where you could put it on your own."If you were prepared to simply go out and copy it because you think it's such a blinding idea without actually evaluating it properly then you can cut a bit of time out of that," added the Briton.The two most recent examples of teams coming out with a development that others then rushed to copy were the McLaren F-duct and Red Bull's side exhaust."Last year where we put our exhausts on from the first test and McLaren had managed to copy (us), by their own admission, by the first race. I guess with hindsight we perhaps should have delayed that a bit longer," he said.The boffin, who has designed title-winning cars for Williams, McLaren and Red Bull, said his new car had performed largely in line with expectations during the first test and could not comment on Ferrari, which seemed to have its work cut out.CLOSE LOOKHowever, he pointed out that lap times could easily be manipulated by fuel levels, particularly at Jerez where each 10 litres of fuel on board equates to around 0.35sec a lap.The Mercedes, he said, would be looked at closely by rivals only if its performance indicated something."If it comes out and goes three seconds quicker than anybody else, yes, of course," he said. "Other than that, simply because its later doesn't mean to say you are going to suddenly show more attention at that than anybody else's."Of course you do look at other cars but I generally find that at this time of the year the main thing to do is to try to understand your own car rather than worry too much about what everybody else is doing."