Important Lobby Settings:
Teams: 2
Buckets: 4
Unlimited:  No handicap'
Small Restriction:  -5% Power"
Medium Restriction:  -15% Power^
Large Restriction:  -25% Power*

Car Specs:
Alternate wheels may be used if the PI remains unchanged.  If much heavier wheels are used, then race brakes and/or upgraded drivetrain options may be used.
It should be noted that the cars with full tire width or full non-engine upgrades are not for the faint of heart.  They have been balanced as they appear on the list.  
The Small Restrictor category will probably be implemented as the fast driver bucket.
   
Super GT:

Aston Martin DBR9:  Stock (825 PI)'
Audi ABT TT-R: Stock (827 PI)'
Audi A4 Touring Car: Stock (833 PI)'
Chevrolet Corvette Racing C5-R:  Lighter rims and driveshaft (817 PI)'
Chevrolet Corvette Racing C6.R:  Stock (823 PI)'
Dodge Viper GTS-R (Zakspeed):  Full tire width (823 PI)'
Dodge Viper GTS-R (Oreca):  Stock (823 PI)'
Ferrari FXX:  Fully upgraded including race tires, except engine (837 PI)'
Ferrari F40 C:  Fully upgraded, but use first piston upgrade (852 PI)^
Ferrari F50 GT: Stock (875 PI)*
Ford GT Mk7:  Fully upgraded (819 PI)'
Honda GT500 NSX:  Stock (859 PI)^
Hyundai FM Genesis Coupe:  Stock (859 PI)^
Koenigsegg CCGT:  Race differential (857 PI)^
Lexus GT500 SC430:  Stock (857 PI)^
Maserati JMB Racing MC12:  Stock (824 PI)'
McLaren F1 GTR:  Stock (848 PI)^
Mercedes-Benz C-Class Touring Car:  Stock (834 PI)'
Mosler MT900S:  Fully upgraded, except engine (819 PI)'
Nissan JGTC Skyline:  Stock (858 PI)^
Nissan GT500 GT-R:  Stock (859 PI)^
Nissan R390 GT1:  Stock (859 PI)^
Opel Astra V8:  Stock (829 PI)'
Pagani Zonda GR:  Stock (825 PI)'
Pagani Zonda R:  Stock (872 PI)*
Porsche 911 GT1-98:  Stock (857 PI)^
Saleen S7R:  Stock (836 PI)'
Toyota GT500 Supra:  Stock (855 PI)^

Bucket list:  
Unlimited:  FIA GT1 (2006+),  FIA GTS (2005-) DTM, upgraded FIA GT2, Ferrari FXX, Mosler MT900S, upgraded GT300
Small Restrictor:  N/A
Medium Restrictor:  FIA GT1 (1998-), Ferrari F40 C, GT500 (JGTC)
Large Restrictor: Ferrari F50 GT, Pagani Zonda R

GT:

Audi R8 LMS: Stock (744 PI)'
BMW M3 GT2 (either): Stock (756 PI)^
BMW M3 GTR (either): Stock (735 PI)'
BMW Z4 GT3: Stock (721 PI)'
Chevrolet Corvette Racing ZR1: Stock (754 PI)^
Chevrolet Monte Carlo Stock Car:  Race weight reduction, brakes (773 PI)*
Dodge Viper ACR:  Race drivetrain, brakes, sway bars, flywheel, air filter, intake, exhaust, flywheel, oil and cooling; max rear tire width (719 PI) [ACR-X build]'
Dodge Viper Competition Coupe (race): Stock (730 PI)'
Dodge Viper Competition Coupe (turnkey):  Race flywheel, brakes, wheels (727 PI)'
Ferrari F430GT (any): Stock (763 PI)^
Ferrari F458GT: Stock (763 PI)^
Ferrari 599XX: Full tire width (787 PI)*
Ford FG Falcon: Full rear tire width, race transmission, brakes, driveshaft (726 PI)'
Ford Fusion Stock Car:  Race weight reduction, brakes (773 PI)*
Ford GT Mk7: Stock (761 PI)^
Holden Commodore VE: Full rear tire width, race transmission, brakes, driveshaft (726 PI)'
Jaguar RSR XKR GT: Stock (752 PI)^
Lamborghini Gallardo LP560-4 GT2: Stock (759 PI)^
Lotus Evora Type 124:  Sport pistons, race brakes, full front tire width (713 PI)'
McLaren MP4-12C GT3:  Stock (744 PI)'
Mercedes-Benz AMG SLS GT3: Stock (724 PI)'
Mosler MT900S:  Race flywheel, drivetrain, brakes, suspension, sway bars, tires, front aero (777 PI)*
Nissan GT300 Z (either): Stock (736 PI)'
Panoz Racing Abruzzi: Stock (759 PI)^
Panoz Esperante GTLM: Stock (752 PI)^
Porsche 911 GT3 Cup ('08): Stock (725 PI)'
Porsche 911 GT3 Cup ('11): Stock (733 PI)'
Porsche 911 GT3-RSR ('05): Stock (744 PI)'
Porsche 911 GT3-RSR ('07): Stock (756 PI)^
Porsche 911 GT3-RSR ('11): Stock (760 PI)^
Subaru Impreza GT300: Stock (737 PI)'
Viper SRT GTS-R: Stock (751 PI)^

Bucket list:
Unlimited:  GT3, GT300, V8SC, Viper ACR, Viper CC
Small Restriction:  N/A
Medium Restriction:  GT2/GT/GTE
Large Restriction:  NASCAR, Ferrari 599XX, Mosler MT900S

Note: taking power out of the GT500 cars will likely result in lower aero. This is fine, because they hit the same speeds on the straights and in the corners with significantly lower aero than the GT1/GTS cars.

can you put the little ' " ± whatever things next to the car names like you did last time? i dont know what you consider to fit in to some of the classes

On it.

LSA if we drive the same Super GT car as in season 1, can we start Season 2 with the PI that we finished S1 with?

Part of me really wants to have last season's PI, but I have reservations about doing that, because we don't know who will be in what cars--and I don't want to turn this into a PI race. What we could do is run some (sorry, I know I keep talking about this) exhibition races--call them pre-season test sessions--and get a head start on PI balancing. I have one season of balancing under my belt, so I should be a little faster at it this time around. There is another problem, though: if only some people show up for an exhibition race, then only those people would get the PI adjustment, ending up being unfair to anyone who didn't hear about the event or those who just couldn't make it. Sorry to say it, but it would be easiest if we started on a blank slate.

Build changes!

Chevrolet Monte Carlo SC: Race brakes, transmission, driveshaft, full tire width(751 PI)^
Ford Fusion SC: Race brakes, transmission, driveshaft, full tire width(751 PI)^

The Viper ACR may get a little boost. It's just a little behind the race cars on handling-intensive courses.

NASCAR Stockers are back to the original builds. Lotus Evora Type 124 included.

Where is my pi?

I think our friend LSA is still working on everybody's PI

The GT2 cars have been removed from Super GT. The speed/handling balance just wasn't right. The one exception is the Ford GT, which has a lot of GT1-like characteristics.