Don't do it. I came from a 3 series and lowered it 1.5" with sport springs. It looked great but the rear tires wore really really fast (no matter how many times I aligned it), and I ended up with some wear to the suspension that I think was irreversible. It remained bouncy even when I put back the stock springs... could never get that nice firm factory suspension back without shelling out some major bucks for new shocks and who knows what else. I regretted doing it and would recommend against it especially on the x.