McLaren was challenging an escape forward style Renault in recently submitted MP4-26 in Jerez on Thursday.
The car was presented by Lewis Hamilton in the Spanish circuit and differs substantially from the version presented in Berlin by Auto Motor und Sport.
There has been speculation that McLaren 2011 was presented in Jerez with a unique exhaust design this season when Renault presented the innovative Renault R31 with best time in Valencia last week.
The correspondent of Auto Motor und Sport in Jerez de la Frontera, said that the rear escape from McLaren had mysteriously disappeared when Hamilton left the pit in Jerez on Thursday morning.
However, exhaust are dating only novelty discovered by journalists when the mechanics had to pause once in front of the docks.
"Just as with the Renault detail is very difficult to photograph", confirmed the German report.
