World Rally Championship promoter ISC is aiming to have four manufacturers in the series in 2011.
In the last decade, there have been as many as seven manufacturers, but ISC chairman Neil Duncanson says that number is too high. He believes that two manufacturers joining Citroen and Ford and a growth in the number of customer teams is the best way for the sport to develop.
"There's no question that I would like a couple of manufacturers to come in and join the two we already have," he said. "But I don't want any more than four. When North One Television came in to the WRC as a television partner in 2000, there were seven manufacturers and I don't think that was effective at all.
"Beyond the fourth manufacturer, the other three didn't stand a chance of winning a rally or even coming close to a podium. I don't think that was particularly healthy for those manufacturers."
Proton, Skoda, Abarth and Volkswagen have all been rumored to be close to a commitment to the WRC in the near future.