So my new diesel arrives in a week, and an independent garage owner I know told me last week about the great performance software available for the diesel. Said it will really improve performance and mileage - all for $700! So I mention this to my sales guy who agrees that these software programs generally really do improve performance, and in some cases, quite noticeably. So i'm feeling good at this point thinking that for an extra $700, I'm going to get a whole lot more vehicle than I thought. BUT (and its a big one), he also said it voids your waranty. Obviously not on if that's the case, but I have read these forums enough to know many members have had these upgrades done. So how do you deal with the warranty issue?