I have the performance exhaust on my car. While the Performance one comes in a box in the pieces pictured, the stock is one solid piece. Stock will fit in the back seat/trunk of an E92 if you drop the seats. E93 it fits with the top down.
Make sure you ask the dealer for your old part back, as some have said -- they try to keep them, in my experience.
LOVE my performance exhaust.
2009 E93 M3 | Alpine White | Novillo Black | 6MT | ZPP | ZCW | ZTP | 19s | Premium Audio | Sirius | BMW Performance Exhaust