I have lowered and added spacers. After much research I went with Turner Motorsports 18 mm spacers. My Style 87 wheels are now just short of flush to fenders. Any wider and I would be throwing junk on the side of the X. There have been many discussions about spacers. Many speak in threads you can seard of 20-25mm spacers but it is always difficult to sort out what wheels they have, if they did both ends the same and what X they have so that it is direct comparison to yours. I did both the same to keep the same stagger. I lowered mine by going with H&R springs and adjustable sensing rods. The sensing rods replace the fixed length rods and 'fool' the suspension to think it is at the stock level though it is lowered just over 1.5". Front is the same drop. Whatever spacers you choose be sure they bolt to the hub and and come with longer lug nuts. I liked the original exhaust but I love the new exhaust. There are also threads where some have changed just the muffler, added and X pipe into existing exhaust or deleted the resonator. Key is if you do anything be sure it does not create an exhaust drone at cruising speeds. If not, you will hear very little difference except when accelerating. There are several youtube videos of different exhaust options.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas