I use San Andreas 2.0 and use this trick to add mods to the game. I must have over 30 cars and my game still runs like a top. I have also found the same trick of converting vehicles from .dff or .txd to .old also works with textures, though i choose not to do that, san andreas has too many textures and doing all that manually takes forever. but here are some cars i have put in my game with this trick, i will also say what they replaced
Chrysler 300c - Admiral
Chrysler 300m - Solair
Chrysler PT Cruiser - Primo
Dodge Challenger - Cheetah
Ford GT - Bullet
2008 Toyota Camry - Greenwood
Mitsubish Lancer Eveolution - Tahoma
1988 Monte Carlo SS - Majestic
1994 Nissan 300 ZX - Elegy
2009 Volkswagen Scirocco - Flash
Lamborghini Murcielago - Turismo
GTA 4 Infernus - Infernus
GTA 4 Comet - Comet
GTA 4 Super GT - Super GT
2005 Toyota Corolla - Bravura
2005 Hyundai Elantra - Perennial
1994 Dodge Ram 2500 - Yosemite
2007 Ford F150 Double Cab - Bobcat
2006 Chevy Avalanche - Landstalker
1992 Chevy Caprice Classic - Premier
1992 Chevy Caprice Taxi - Taxi
1988 Dodge Diplomat Taxi - Cabbie
1992 Lincoln TownCar - Elegant
1995 Dodge Viper R/T - Banshee
1989 Honda Civic - Blista Compact
2009 Nissan 370Z - ZR350
1992 Chevy Camaro Iroc Z28 - Buffalo
1999 Honda Prelude - Cadrona
2005 Mazda RX8 - Club
2005 Dodge Neon - Sultan
1989 Pontiac Bonneville - Vincent
1970 AMC Javelin - Stallion
2009 Chevy Camaro - Clover
1995 Volvo A740 Wagon - Stratum
2007 Honca Civic Coupe - Previon
1993 Ford Mustang GT 5.0
2005 Mercedes S500 - Washington
Theres more... I jsut cant remember them right now
i jsut remember the tutorial said that there was a certain number of cars before the game is no longe rplayable, whats the limit? cuz i got a ton of cars and im donig ok
PC Specs
2.4 GHZ Dual Core Processor
NVidia GeForce 8300 GS 128 MB
256 MB Ram
DirectX 10 SoundCard