That's because Sebring is generally used by the biggest teams as a tune-up for June's 24 Hours of Le Mans. The Floridian race might only be half as long, but the sheer brutality of the racing surface makes it a great test of a racer's durability, hence why it's a popular stop on the way to France.
As it turns out, it was the track's roughness that was the reason Nissan decided to piggyback on one of Audi's tests at the south Florida circuit, Autosport reports. But an issue "to do with the engine mounting" on the front-engined GT-R LM racer sidelined the team.
"It was actually a very minor thing, but we just don't have a spare here," Technical Director Ben Bowlby told Autosport. "We've spent a lot of time at Austin, which is very smooth, so we wanted to come to a particularly harsh environment like Sebring."
While it seems rather silly to test somewhere in an attempt to "accelerate the durability cycle" without packing a full complement of spares, the rough surface of Sebring has a tendency to wreak havoc with even the most reliable of parts.
Nissan did manage to run a total of 68 laps over the course of two days, with drivers Marc Gene and Olivier Pla at the wheel. At present, Nissan won't be running the GT-R LM in the actual 12 Hours of Sebring – it's first race outing will instead be at the 6 Hours of Silverstone, running next month.