I would like to ask a few questions:
1. Are you planning to replace most of the cars?
2. Could you try to make an saving place in some of the houses at the village? Saving game on the sewers feel weird
3. Are you planning to create an russian radio station? (in the future of course)
I'm not agree with first suggestion! If @MIXAZZZ remove excisting vehicles, for those using Simple Native Trainer most of its features will become incompatible because if anybody for example tries to spawn any of original GTA IV cars via SMT and corresponding vehicle was removed, this will most probably make GTAIV to crash! I've had encountered this already with Object Spawning menu (on current version 1.3.1), where I tried to spawn an object from original game (that is probably removed) and game stopped working and crashed immediately after I've pressed Num 5 to spawn selected object! So I will have a recommendation for @MIXAZZZ - for compatibility with Simple Native Trainer he do not remove original GTAIV vehicles to prevent similar crashes if someone using Car Spawner on Simple Native Trainer. Adding new Russian vehicles - yes, but do not remove original ones! Above I've explained why.