The reasoning was the same as that chosen by Audi and Peugeot for following the diesel path. By increasing fuel efficiency, the car could run longer between pit stops, reducing the amount of time standing still in the pits. The Panoz Q9's lack of testing time before the first run at the 24 Hours of Le Mans, meant it just failed to qualify. Later that year, Panoz entered the car, which was nicknamed "Sparky," again for the first running of the Petit Le Mans where it qualified and finished second in GT1 behind a Porsche 911 GT1. Unfortunately, the battery technology wasn't advanced enough at the time; the entire right side of the cockpit was filled with them. Although there were hybrids that popped up on the track now and again over the years, it would take another decade for hybrid race cars to run at the top levels of the sport.
[Source: American Le Mans Series]