Offtopic: What small change in a car, would deliver a 3.5% difference in top speed? (Hint it's a Lamborghini...)

Well I know it is offtopic but that small detail in question is merely putting the roof up on a Lamborghini Gallardo Spyder - 190 mph roof down and 197mph with the roof up gives a 3.5% or 7mph increase in top speed....wow!

Small changes big impact, now where is my piggy bank... :-)

So to bring this slightly round to IT topics - what change could you make in your business either in terms of process or technology that could deliver a similar impact?