Somona is also the home event for Bourdais' main sponsors, internet security specialists McAfee, which is what made the call over who got the single engine for the race so difficult - and the team's jubilation when Chevrolet stepped in to provide a second power unit for the race.
"Obviously, with Sonoma being such a big one for both myself and Sebastian sponsorship-wise, it's my home race with TrueCar [and] on Sebastian's side there's the McAfee thing," she explained. "Chevy are just doing us a huge favor in stretching their own resources to help us out.
"All the other [TrueCar initiative] girls are going to be there. Virgin has come onboard. We have lots of fun media stuff we're doing. And they're based there, as well. For us it's like the biggest race of the year."
There's still the small matter of getting used to the track however. Once called Sears Point, and most recently going by the name of Infineon Raceway until the end of a ten-year naming rights deal in June, Somona is virtually completely new ground for Legge.
"I did about 20 laps of Sonoma back when Sebastian was testing there about a month ago. that was really just to kind of do a shake-down," she said. "Luckily we have the test there next week.
"I've just been training physically to get ready for it," she explained. "I've been driving on the simulator. I've been watching YouTube videos. I asked the team to send me some data. I mean, I'm doing everything outside of the car that I can possibly do. There's no substitute for actually driving the car."
The Sonoma track layout will feature a few new tweaks to it
this year to help improve overtaking opportunities after a very static race in 2011. Understandably, Legge had no view of the changes given her lack of previous race experience here.
"I can't really comment on how it's going to affect it racing-wise or anything like that," she said. "But I have to believe that the powers that be know what they're doing and they've made the changes for the better. I don't think they would change it for the worst, or at least I hope they wouldn't. I think it will probably be a good thing."
And after Sonoma, there will be only two more races remaining in the 2012 IZOD IndyCar Series season: Bourdais will drive for Dragon at the road course in Baltimore, on September 2 and then Legge gets to drive in the season finale at Fontana two weeks later.
"Yes, I'll definitely be driving Fontana, the last race of the year. And Baltimore at the moment is scheduled to be Sebastian. Unless anything changes, that's the plan," confirmed Legge.