one more question , Single Exhaust vs. RSB which would you guys consider better performance mod ? i know its a hard question as they both deal with different concepts of tuning a car
You're right. They are two completely different mods.
Handling vs power gain
Handling vs aesthetics/sound
So it all depends on what you would rather have. No one will see you have a RSB so if you are looking for something that will get others to notice you then this won't do it.
The RSB will benefit you if you take turns at a faster than average pace otherwise you won't notice it
The exhaust will be something you notice whether you get on it or not. Also I don't know if the exhaust will give you that much of a power increase unless you are running alot of mods. I could be wrong.
Value? The RSB will give you more bang for your buck.
Cheers, sounds like you have some fun mods coming ahead.