ZondaLM
If you have not bought the Toyota GT-ONE already then I would suggest purchasing the PlayStation Pescarolo C60/Judd Race Car 2004. Eventually you will find a black Toyota GT-ONE in the used car lot for far less than $4,500,000. Until you do, this car is of equal performance.
The Judd 2004 Racecar has a better handling in my opinion, so if you are not used to drive the very fast LMPs, you might give this one a chance.
The GTOne - if you can handle it - is more fun to drive, though ...
[edit]nearly forgot to mention - nevertheless, i love the GTOne more than the Judd'04. The latter one seems to be the better car, but the GTOne is way more fun.[/edit]
Regarding Endurance-Races generally, you might want to test two different tire-compounds first, usually medium and hard ones.
Try to do some laps with the hard ones at first, get a feeling how they effect the handling and then switch to medium ones (if you want to, that is).
If you are starting from the pole, you might want to start with the medium-tires first in order to open a gap quickly. You'll probably will have to pit one or two laps earlier than your opponents, but if you are fast enough, you'll get out in front or around place #3.
Now, change to the other compound you choose (usually the harder ones), don't refuel if you have to and get out again. Be careful since your car "has a different handling" now, but you should be able to get in front again when your opponents are pitting. If things work out, you'll be able to do as much laps as your opponents do, sometimes one more - and after three stops you'll have the same pit-strategy as your opponents - and be way in front of your opponents.
Now, things do not always go as easy as it might sound, but it's a good strategy if you are new to the Enduros. I'm used to have two different compounds for every LMP-car since I like to switch between them to have a flexible strategy and I have scored some wins just because I could go way faster for a short time than my opponents did.
Another thing you should keep in mind is the handling of your car if the gas tank is nearly empty. The handling might improve (or get worse), but you can save a huge amount of time if you refuel after two pitstops rather than every pitstop. Check how much fuel you have used (if you enter the pits, choose to refuel and when the gauge comes up, memorize how much fuel you have used and calculate how much laps you have done.
You'll work out how much you used in how many laps and how much you have to refill after some two to three pitstops - and it makes the races much more fun, too.