My source, which is a British magazine of January, 1921, simply refers to this drawing as 'The Car of 2021' but without any further information about it
Thanks for the PM! I think it's time to call this one solved. My source (German
Automobil-Zeitung, 30 January 1921) cites to the same British magazine (
Light Car & Cyclecar, 1 January 1921), yet refers to the vehicle as 'The Car of 2121' and identifies it as 'Electric Touring Car Model 2121'.
As you've found the original source (or at least the one cited to by my source), I'll accept that as authoritative and award you the point.
Here is what was published by
Automobil-Zeitung. Please post an image of the
Light Car & Cyclecar material if you can.