i currently drive a bmw 318i sedan and can longer put up with the cars appaullling 4cyl engine. i have done some research and am considering a cold air intake kit, an air intake system or just a rpm performance tune chip. the car is only used for city driving so needs to be affordable to buy the upgrades whilst still being cheap to run. Any other suggestions would be greatly appreciated along with opinions.
thanks in advance.
thanks in advance.