As I've mentioned before, back in South Africa I owned and thoroughly enjoyed a BMW R100RT motorcycle. This gem gave me many thousands of miles of motoring pleasure, until the danger from other motorists in the large city where I was living at the time convinced me that it was better to give up the bike and remain alive! I understand things haven't improved since then . . .
Be that as it may, BMW first introduced a flat-twin, horizontally-opposed so-called 'Boxer engine' in its R32 motorcycle in 1923. The same engine, with a few modifications, continues to power some of BMW's motorcycles to this day. Recently the company decided to celebrate 90 years of the Boxer engine by producing a custom bike.
This is the result. I recommend watching in full-screen mode.
You can read all about it here. Suffice it to say that, despite my fused spine and nerve damage in my left leg, I'd give my eye-teeth to own and ride one of them! Drool-worthy . . .