<P> The 1995 McLaren Mercedes MP4 / 10 was one of the first cars to feature a "midwing", using a loophole in the regulations to mount a wing on top of the engine cover . This arrangement has since been used by every team on the grid at one time or another, and in the 2007 Monaco Grand Prix all but two teams used them . These midwings are not to be confused either with the roll - hoop mounted cameras which each car carries as standard in all races, or with the bull - horn shaped flow controllers first used by McLaren and since by BMW Sauber, whose primary function is to smooth and redirect the airflow in order to make the rear wing more effective rather than to generate downforce themselves . </P> <P> A variation on this theme was "X-wings", high wings mounted on the front of the sidepods which used a similar loophole to midwings . These were first used by Tyrrell in 1997, and were last used in the 1998 San Marino Grand Prix, by which time Ferrari, Sauber, Jordan and others had used such an arrangement . However it was decided they would have to be banned in view of the obstruction they caused during refueling and the risk they posed to the driver should a car roll over . (It is rumored that Bernie Ecclestone saw them as being too ugly on television and therefore had them banned). </P> <P> Various other extra wings have been tried from time to time, but nowadays it is more common for teams to seek to improve the performance of the front and rear wings by the use of various flow controllers such as the afore - mentioned "bull - horns" used by McLaren . </P>

What is downforce and why is it important in f1 vehicles