This Estoril Blue 335i isn't even an F30 with M Performance body parts but simply a regular M Sport, so that would be 3 levels more agressive
Well considering that the F20 Performance Studie showcar was a show-off of the future ///M135i, so is the recenlty leaked F30 M Performance Studie a show-off of the ///M335i. If that is confirmed, we can say that the M Performance kits on these F20 and F30 basically take over the M Sport exterior kit except for some minor details (rear bottom end which isn't black but painted in the car's color and with a few vents, stickers on the body...). Just like the current 335is is very close to the M Sport 335i and the Z4 35is very close to the M Sport Z4. Take the stickers away and they are extremely close to their normal M Sport versions.
Upwards on the scale, BMW would basically have to enhance the style just one and a half notch up from the M Sport to differentiate the M3. Not difficult with a specific ///M front bumper (with the big 'mouth'), rear bumper with quad exhausts, side gills and, most of all, heavily widened wheel arches (seen on the M3 spies).
So if this really is how the M Performance will look like, then I wouldn't worry about a confusion between ///M335i and M3
but much more about a confusion between ///M335i and M Sport 335i, and even more a confusion between ///M335i and M Sport 335i with M Performance accessories if they will be available separately (it becomes complicated
) Well Audi for instance seems confident enough to issue the S versions of all of its very last models with the exact same exterior aero kits as the simple S-Line (only differences in grilles and rear exhausts).