Actually....there is a separate part number for an e90 fitment:
Product Name Model Price
Akrapovic Evolution Exhaust System BMW M3 E90 S-BME90M3E £4,271.00
Akrapovic Evolution Exhaust System BMW M3 E92 E93 S-BME92/3M3E £4,271.00
Akrapovic Slip-on Exhaust System BMW M3 E90 MTP-BME90M3H £2,571.00
Akrapovic Slip-on Exhaust System BMW M3 E92 E93 MTP-BME92/3M3H £2,571.00
Replacement Lambda Probe (required if replacing OEM cats and using OEM ECU Tune) P-LBSB3 £282.00
Anyways... that is still one helluva deal so good luck with the sale!
and free bump