Doornbos sees his future with RBR

Doornbos was Jordan's third driver last season, before stepping into a Minardi racing seat midway through the season. But he admitted he found his work in 2005 frustrating at times.

"It's a great experience to race in Formula One, but not so much being in the back," Doornbos said at the Autosport International Show.

"Sometimes it was quite difficult to see the blue flags waved at me and see the other cars disappear in the horizon, while I was already going flat out."

But Doornbos had no regrets about his Minardi drive and said his signing as Red Bull Racing's third driver was a further step up the ladder.

"I was more frustrated in the beginning of the season, at Jordan, as I was often faster than the two racing drivers, who were inexperienced but were still racing. So when the chance came to race with Minardi, I didn't hesitate for one second and took the opportunity."

"Now with Red Bull it's a different experience, you can't compare the two worlds. When I first did a factory tour in Minardi, it took me 20 minutes. At Red Bull, it was more than an hour.

"The experience I am getting from testing at Red Bull Racing, all the testing, all the mileage, will definitely help me in the future. I can learn a lot from David Coulthard - you know how precise he is for details - so most certainly testing for Red Bull is a great opportunity for me.

"And, yes, I look forward to racing for them one day."