That is an impressive lens flare! 👍🏾
And totally unexpected. I've had two identical Rolleiflex's over the years, both 3.5 Tessar. The first was my first TLR, roughly 1976 to '79, when I regrettably had to sell it to fund a new 35mm SLR. Ten years ago, I found one that was manufactured about 3 months after the first one. TL;DR I've shot a fair amount with the Tessar over the years and have never had flare before.
I'm still not sure whether it was from direct sun or the highlight off the top of the car. We're in the annual gray season here - Graypril, May Gray, June Gloom - due to the marine layer, so I had kind of anticipated much softer lighting. By the time I got around to that particular car the lighting was pretty harsh. That angle was the only one I could find without direct reflections into the lens from the headlights, windshield frame, etc. I guess it points to the fact that you can own a camera off and on for decades, and still discover attributes and anomalies along the way.