Montoya had high hopes early on
This was supposed to be the season when it all came together and they won the Formula One championship.
But with two races to go in '04, Montoya is a distant sixth in the Drivers Championship, and Williams BMW is scrapping it out with McLaren Mercedes for fourth in the Constructors Championship.
At the start of the 2004 season, when Williams unveiled its radical looking FW26 with the "hammerhead shark" nose, there was so much optimism.
"Yeah, there was," Montoya told ESPN.com. "If you look at what happened in the previous year, how we finished, and how the car looked in testing, you would have imagined that this would have been the year."
Last year, with three races to go, Montoya was only one point behind championship leader Michael Schumacher. It all went wrong for Montoya after that and he ended up third in the points, but he had proved the potential was there.
But after a fairly strong start this season the Williams BMW challenge faded.
"In the first few races the car was quite competitive," Montoya said. "It was ahead of the rest of the Michelin runners and it wasn't far from Ferrari. But it took six months to get any development in the car."
The "B" version of the Williams FW26, which came out in midseason, was an improvement, but the team has been playing catch-up all year.
"The car is more competitive now," Montoya said. "It is competitive compared to the other Michelin runners, but we are still trying to catch up. If you start doing catch-up from the beginning you are always going to be behind because they (the other teams) are not sitting with their hands crossed -- they are putting more things in their cars as well. Unless you do big steps, you are never going to get there."
While the car wasn't great, Montoya is more than satisfied with his driving performance.
"Performance-wise we couldn't do a lot more than what we did," Montoya said. "I am pretty pleased with the way I drove during the season. I had very good races when I was really driving the wheels off the car, and the car allowed me to do that.
"At some races it was more just getting the car to the finish because you couldn't even push it. Every time you pushed it would step out, and you get to a point where you think, 'If I try any harder I'm going to go off.' You are limited to what the car allows you to do."
The car, Montoya said, has been good enough to finish in about fifth place. And that is frustrating to a guy who believes he has the talent to win.
"It's frustrating because you want to win and you are here to win and you know you can win because you have done it before," he said. "It is quite hard because ... you know if you put in a good qualifying you are (only) going to be P5 or P6. We have done P2 this year a couple of times. Look at Monza, (Italy) I qualified P2 and I ended up P5. In China I qualified P11 and I finished P5. So that is where the car is. Ralf (Schumacher) is running P5 as well, so that is where the car is at the moment."
Montoya has kept his motivation up by driving as hard as he knows how.
"I love driving and I just do it because I love it," he said. "Between going out and just driving around and going out and pushing, I will enjoy myself more if I am pushing."
A year ago here in Japan, Montoya led the first nine laps before retiring with a hydraulic problem. This season, though, he has not been at the front challenging for wins.
"It would be hard if the other car (in the team) would be winning races and you were P4 or P5," he said. "But if both cars are struggling it is not so hard. If you are the problem, you need to work on yourself. But when your teammate has won races and you have won races, and you have been close to winning championships, and suddenly the two drivers are miles back, it really says something."
There have been no wins for Montoya this year and only two podiums. He says the British Grand Prix, where he finished fifth, has been his best race so far in 2004.
"Qualifying wasn't brilliant," he said, "but in the race the car was really good and it allowed me to push."
As for the final two races of this season -- in Japan and Brazil -- Montoya hopes that Williams BMW stays ahead of McLaren Mercedes in the Constructors Championship. Currently they have 64 and 58 points, respectively.
In the Drivers Championship, Montoya is in sixth place with 46 points, and he is aiming for Fernando Alonso who is in fourth place with 50 points.
"I want to finish ahead of McLaren and try to beat Alonso," Montoya said. "It will be quite hard because before we were scoring six to 10 points easily, so it was easy to make up the difference. Now we are scoring three or four points. Unless he has a major problem and we had a brilliant race it will be hard. But we will give it a try."
Dan Knutson covers Formula One for National Speed Sport News and ESPN.com.