hahaha.
are u an honest player? never try to read those online guides everything? if yes, then i salute u bro... so patient wakakaka :D respect dude.
the cars in san andreas depends on what day/days it is. the problem is, so far i only understand that they are generated at random where a certain model appears for a few days. if u dowan to wait for the cars to change, what u can do is, load/save game often la. :D there is even a map (not in the game) showing where u can get ALL the export cars for free (means not having to hijack them from ppl). i dont think u'd be interested tho. hehe.
Blades are often used by Grove Street gang members around Ganton, and also by the San Fierro hispanic gang (T-Bone Mendez's gang). When u cant find a car by staying in one city, drive around the whole map (all of san andreas) and try (hijack) every vehicle that u've never seen before. usually by the time u circle around the place u started, u'd have passed by at least 2 models which are wanted for export. trial n error. :D more fun.