Mind if I bump?
I just did the Amateur GTWC with a completely stock Nissan Calsonic Skyline, and some races late in the season were ultra-fun. The lineup consisted of a Dodge Viper Team Oreca and Corvette C5R, which mainly dominated the straights, a Pennzoil and another Calsonic Skyline, and the Lister Storm.
In Seattle, I had trouble with the Pennzoil for long, and ended up chasing the Viper from a 3.1 second deficit on the final lap. Thankfully, it was running on completely worn out tires, and I managed to turn that loss into a 2.4 second win. The following Midfield race was a bigger toughie, as I was 6-7 seconds down for most of the race until the Viper pitted, and even after that, I kept getting pressure from the other Calsonic (which never pits, by the way) and the Corvette, who had pitted earlier and charged from behind the pack all the way into second, losing only 0.8 seconds to me. The entire field finished within less than 5 seconds.
The finale at Grand Valley was the most awesome, though. Just like normal, the Viper and Corvette escaped early, but the Corvette had grip problems and pitted already on the second lap, leaving me to chase the Viper and focus on holding up the Pennzoil and Calsonic, which were coming pretty close to my tail end. The Viper and Pennzoil pitted on lap 3, but during the fourth lap, when I was making up gap in the lead, the Corvette charged back again, passing the Lister and Calsonic easily, but thankfully it had to do another stop, and my victory seemed to be coming for sure...
...Well, think again. The Viper had now come with a horrific pace from behind, also passing the Lister and Calsonic with ease, and by the first sector of the final lap, the gap was only 0.5 seconds.
The Viper then forced itself past me on the hairpin leading to the left-right-left section before the tunnels. I re-passed him on the final left of that combo, and held him off in the following corners and the bridge too, even on the orangish tires. In the left-right combo right near the end, I managed to make up gap, but I was still afraid that it wasn't enough, and feeling pressured, I slid off the track at the last turn.
Still I had just enough pace to finish the race in first and earn the full prize for that hard work.
For more experienced drivers, even using the Calsonic may be too easy, but there's always even slower racing cars to use, or even road cars.