an important part, steer clear of any deep puddles! Years ago that was my first modification. I removed the resonator box and clamped a length of the wifes tumble dryer hose (she never noticed it was shorter!
) to the end of said pipe and clamped this to the inner wing area near the headlight. Made a difference too just as you are mentioning, this eventually lead to the BMC CDA I now have, that's been on for about 4 years now.