GANSEI,
With all the new improvements on the new G4RS, it looks like a better car in your hands since you've broken the track record. Congratulations!
Is the track treated with any traction compound? Since you are using 37shore tires Front/Rear, it doesn't seem like traction compound is used on your track. What size tire do you start with??
I still race the G4S and don't plan to get the RS because I don't race enough to warrant spending another $400.
Good luck.