You cannot, GTA SA has a much lower graphic system then GTA IV, plus the cars in GTA IV have more addons than GTA SA.
by modding them
beat missions
no
You can't unles you have a mod
no
i dont think u can
gta sa pactch.indiavichels.exe
pretty much any kind of veihcal
fire man
search gta sa cheats then look for car catagorie.
just stand in front of the export wanred sign and a buying option will appear.