Put 1jz or 1jzgte in your car, make it unique from other roaming yarises, make it one & only jz yaris of pakistan, then you will have a peace of mind ...
Dude, why don't you understand that these are economical cars, these can't be modified that much other than minor cosmetic changes, there engines are to give economy and there purpose is to go to point A to point B with fuel saving techniques, don't fiddle the factory fitted stuff specially with these types of engine modifications, you will ruin your brand new car and will end up on wasting money to get it back to.original or might not get it like factory fitted stuff ...