I've run Defi gauges on previous cars and they are lovely, but if I were wanting to add a boost gauge to my 1M, I'd buy a P3 gauge. In fact, I did
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.