Valtteri Bottas will be running the only version of a new front wing on his Williams in Hungary.
In some teams, when only a single copy of a new technical innovation is available at a grand prix, the driver that gets to use it is often selected by the toss of a coin.
And other teams, like McLaren, alternate the fortunate driver from race-to-race.
Finn Bottas is quoted by Turun Sanomat newspaper: "We have a rule that if something new is available only for one car, it is the driver who is highest up in the points."
He and teammate Felipe Massa are closely matched in 2015, with Bottas just 3 points ahead in the standings after Silverstone.
Williams is hoping the new wing will help the team have a better-than-expected weekend in Hungary, having acknowledged that the tight and twisty circuit may not suit the FW37.
However, Bottas said: "We don’t want to write the weekend off before it has even begun.
"Last year I was third here in qualifying and the race also went well. Hopefully the new front wing will improve our downforce in the way we want it to, as it would be a big help for us on this track."