Yepp, Just go to C:\Program Files\rFactor\GameData\Vehicles\FSONE09\2009\Equipos\VodafoneMclaren\VodafoneMclaren_02
That the files:VodafoneMclaren_02extra3 and VodafoneMclaren_02extra4 out of the VodafoneMclaren_02 map.
Rename VodafonMclaren_02extra3 to BrawnGP_22extra3
Rename VodafonMclaren_02extra4 to BrawnGP_22extra4
Then go to C:\Program Files\rFactor\GameData\Vehicles\FSONE09\2009\Equipos\BrawnGP\BrawnGP_22
take out the files: BrawnGP_22extra3 and BrawnGP_22extra4.
Rename BrawnGP_22extra3 to VodafonMclaren_02extra3
Rename BrawnGP_22extra4 to VodafonMclaren_02extra4
Then put the renamed files into the teams that the begining of there names says and you will have Jensons helment on the Mclaren and Heikki's on the Brawn.
Good Luck.