One take-
You are driving a nice car for a HS Junior!
$1800 is a lot for the exhaust and other parts - but then again - pretty much all the aftermarket stuff for a BMW is pricey. Have you tuned your car? I debated about tuning the X5, but i have other cars I drive and so lost interest in modding the X5. I also have an M550 and a Porsche Cayenne GTS.. both of which are stock and will rip the headlights out of the X5…
But I do believe you can get a tune for the X5 from tuning freaks.. the BM3.. it’s like $800 or so?? Probably adds a LOT of power to the car. I’d do that before an exhaust.
What wheels do you have?
Ours has the staggered 20’s. They look really beefy with the painted wheel arches. I might do that before exhasut as well.
Good luck on your mods!
And study hard and get good grades in HS and go to college!! If you want nice cars - they are $$. You will need a good job to pay for them!