Of the 4 people ive met with the chip, all 4 say its over hyped.One guy even said his 525 dynoed only 5 hp more then stock.Another said he couldnt feel the difference at all.Seems like you really gotta believe hard for it to work.Ive been thinking of getting it for months but am still up in the air. Please keep us updated on your results. patrick 89 535i