Well, I've finally managed to make my own replica. It's a first attempt, so it's not going to be the best, but I've had this idea for a long time (even before the hacking started). I hope this is acceptable enough to count as a legit reason for bumping this thread. Enjoy!
'12/'13 Chevrolet Corvette Grand Sport Coupe
Based off the '06 Chevrolet Corvette Z06 C6
First of all, you need to buy a Corvette Z06 from the NCD. Change the oil if you so wish, but I didn't. Fit a set of Boyd Coddington Wheels Legacy F-09 wheels, and paint them Blade Silver Metallic. Alternatively, leave them and paint them another color later. You should only need to purchase a fully customizable transmission and suspension. This vehicle also uses the stock Sports Hard tires to simulate the Goodyear Eagle F1 Supercar Run-Flat tires.
Transmission settings:
This Corvette GS replica uses the standard 6 speed manual transmission. Here's the ratios:
1st: 2.970
2nd: 2.070
3rd: 1.430
4th: 1.000
5th: 0.710
6th: 0.560
Final Drive: 3.420
The top speed in the top right should read 309mph.
Suspension:
The Corvette Grand Sport uses Z51 suspension, so set it up like this:
Spring-Rates: 9.2 F/11.3 R
I was unable to find a definitive setting for the toe and camber, but this page may help:
http://www.digitalcorvettes.com/forums/showthread.php?t=109306
Thanks to ich122 for letting me know the suspension settings!
Once that is completed, apply a power limiter to restrict power to 430HP and add ballast until the vehicle weighs 1502kg.
Options:
This Corvette Grand Sport replica is unique in that you can choose the options you want on it. These options are based on the actual options on the 2013 model Corvette GS Coupe.
Colors:
You can choose from these colors on the GS:
Arctic White (Use Summit White from the Camaro SS)
Blade Silver Metallic (Corvette ZR1)
Black (Camaro SS, Corvette Z06, Corvette ZR1)
Cyber Gray Metallic (You can use the Cyber Gray from the Corvette ZR1 and Camaro SS, but the Cyber Gray from the Corvette Stingray is a darker shade that closer matches the real paint color)
Torch Red (Corvette Stingray, Corvette C5)
Night Race Blue Metallic (Closest color I could find from Chevrolet was Le Mans Blue Metallic from the Corvette Z06)
Inferno Orange Metallic (Camaro SS)
Velocity Yellow Tintcoat (Corvette Z06)
Crystal Red Tintcoat (Use Red Jewel Tintcoat from the Camaro SS)
Supersonic Blue Metallic (Closest color I could find from Chevrolet was Aqua Blue Metallic from the Camaro SS)
Wheels:
The Boyd Coddington wheels are the closest to the GS wheels. Paint them Blade Silver Metallic for the base GS wheels. Alternatively, you may want to paint them black or chrome for the optional wheels. For 2012 models, you can paint them Cyber Gray instead of black, except for Centennial Editions.
Extra Options:
Other options are available to personalize your Corvette Grand Sport.
Eagle F1 Supercar GEN2 Run-Flat tires: While it may not be possible to replicate the Magnetic Selective Ride Control in GT5, it is possible to fit Sports Medium tires to replicate the Goodyear Eagle GEN2 tires that come with it.
Genuine Corvette Accessories Full-width Racing Spoiler: If you wish, you can install rear wing type A from GT Auto to get the GCA full-width spoiler on your Corvette.
Special Editions:
You may want to go for certain option combinations to replicate special edition Corvettes.
60th Anniversary Design Package: Select Arctic White paint with your choice of wheel color. Choose the GCA full-width racing spoiler. Unfortunately, the ZR1-style spoiler is not available. It is also not possible to choose the stripes for the 60th Anniversary Stripe Package.
Chevrolet Centennial Special Edition: Select your choice of Black Metallic paint (real-life car has Carbon Flash Metallic paint) with black wheels. Do NOT select the GCA racing spoiler.
This is my first replica, so it may still be a work in progress. The weight distribution may be incorrect and the suspension settings for the real GS is not known. This is also not a true replica, for while the GS uses the LS3 engine, the Z06 has an LS7 engine with higher torque. As such, the torque will almost certainly be incorrect. If you're running at 2.11 however, it may be possible to swap in an LS3 from the Camaro SS. Finally, don't forget to shift at 6,500rpm.
I hope you enjoy this replica!