I kind of agree with my Glue Sticks buddy here. This comment, though accurate, is mostly irrelevant unless you have addressed all the weaknesses of your specific car "a light car is easier on equipment than a heavy car". Problem is, unless you find a team that has endurance raced one and they pass on all those common failure points (most are more than happy to), you will only know the things that commonly fail on the street (about every car has an enthusiast forum). Maybe tell us what it is and we can connect you with a team that does or has campaigned one?
So spend your time as mentioned on safety and reliability. Make sure all the wheel bearings are good and bring spares. Check every single front end/steering component and if not available at Autozone, stock, in BFE...acquire spares. In fact, any sensor, ignition or fuel injection component that cannot be had at said Autozone...acquire spares. Hey, if it is a BMW, acquire two spare ECU's. Make sure the cooling system is in perfect condition.
The point is you will have problems on the first race (and likely many others) but try to mitigate downtime when you do. Then consider replacing glass with lexan. 100-150#'s of lightness is not the difference between that ball joint letting go or that tire not making the full race.