I'm sure the drink pump function has existed for a while, but pre-90s F1 cars hardly label their buttons/switches, so you will have to know by knowledge. But here's an MP4/6 all the way from 1991, and as you can see:
The old cars had them on the cockpit rather than the wheel. But that changed in the late 90s:
Well, it’s kinda real. The MARC Cars II V8 been available since 2018. It was developed during that 2016/2017 timeframe. The original Marc Cars V8 Focus and Mazda 3, been around since 2013/2014. So, a little bit before PD developing the Mustang Gr.3
Maybe a drink button on the wheel. The MARC Cars are built for endurance racing.