I guess that means that you hadn't informed the insurance company about the modification - insurance will pay out so long as all your mods are declared, so no need to stick to the standard exhaust (and technically you're talking about modifying it in any case ;-) ) if you don't want to just because of insurance...
2011+: VO 1M Coupe, many toys, Evolve Stage 3. 2008-2011: 135i M Sport Le Mans Blue / Lemon / HGSL. Comfort Access, Auto−Dim, Elec Seats + Memory, Lumbar & Heating, PDC F+R, Xenons + Adaptive, Cruise, Nav Pro + Assist & Online, Voice Control, Bluetooth, DAB,6 Disc, Prof Hi−Fi (L7), USB/audio interface, BMW Performance Carbon Fibre interior, Evolve OBD remap - 390bhp. Also in the family: Land Rover Defender 50th Anniversary 4.0 V8, 11 Mercedes E Class Cabriolet Sport.