I have a 530 and want to make it quicker, what would people recommend I do to it i.e. superchip (how much difference will they make?) does anyone have one? would it make much difference to the fuel costs? what would be the new 0-60 with chip or upgrade?
Thanks
Forgot to mention it is an E39

The only chip I have found that will not void any warranty or recall or cause unnecessary problems is from Dinan. These are specially made for BMW's and would not void the factory warranty if the car was new. Their website will give you all the details you will need and they even have a phone number listed that you can use to ask for detailed information.