[Chris Angle]

Good evening Moriz!

The steptronic buttons to cange the 'gears' up are not on the direct opposite of the downwards buttons, but a little closer to the midst of the steering wheel on its backside! Their colour is silver, too, as on the front. If you can't find find them by touching then take a mirror and watch the back of the steering wheel.

Both frontside buttons will decrease the gears
the two backside buttons will increase the gears

Greetings from Germany Christian