One of the first things we were told during the briefing for the new Mercedes-Benz A-class sedan is that there are four ways to interact with it. Well of course there are, we thought, mentally ticking off the controls: steering wheel, accelerator, brake pedal, clutch-wait a sec, could this sporty little sedan actually have a manual transmission? What the Mercedes rep was actually talking about is the company’s new infotainment system: Mercedes-Benz User Experience, or MBUX for short.