And keeping it clean is probably going to give the biggest performance "gain" per £Just as a thought, why not use the money you are going to spend on aftermarket stuff, on car care products? that way you will keep the car looking mint and well looked after, then in 2-5years when you come to sell it, you will get more money in your back pocket? thus resulting in more wonga to spend on a nippier motor?
just my 74p's worth.