I bought mine here:
STAINLESS STEEL BMW X5 E53 TWIN EXHAUST TAILPIPE TRIM on eBay, also Exhaust Components, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles (end time 07-Apr-09 20:02:59 BST) Bargain “! Considering the changes it makes to your X5
All I had to do was cut the tips of the exhaust, the bit that bends down”! Then proceeded by sliding the tips in, tighten the bracket and also welded the tip to the muffler for safe keeping”!