Man, do I have the relevant story to this question!
While I was in college, me and some of my friends went for a trip to a beach town. It’s common to rent Vespa-like two-wheelers and drive them around the city as it offers the best scenic views along with the added bonus of avoiding traffic. So, we were six people, me and two friends of mine were driving, all seated in pairs of two. Riding pillion with me, was a guy (a friend of mine) who was supposed to be navigating for me.
Now, the vehicles we had rented were not in great condition, because these are used by tourists every day and ours kept dying down sometimes if I didn’t accelerate for a while. This was while it was dark out and street lights were minimal.
Some of the terrain was quite hilly, and we were coming down just one of these slopes when I stopped accelerating (because otherwise I’d be too fast) because of which the two-wheeler sputtered and died, which meant that the headlights also got switched off with that. We were still at a fair speed though, as we were going downhill, and within seconds, there was a blind turn in front of us and we almost crashed into a car that was coming in from the other side, without any signal. The car driver sped by and cussed me out for being an incompetent woman.
So, this guy who’s sitting behind me suddenly pipes up that, even though the car driver was in the wrong ‘right now’, he was still right about the fact that women couldn’t drive. And he followed that up with advice about what I should have done (I don’t remember what he said). You may ask, why it was that he was sitting behind me then, if he knew it all so well? Of course it was because he couldn’t drive, never had driven a vehicle in his life!
So, let’s get this again - this guy, who couldn’t drive, decided that it was OK for him to tell the woman who was driving the vehicle he was sitting on, that women couldn’t drive and he knew better just because he was a man.
This was the most egregious example of mansplaining that I remember facing, and I’ve faced this multiple times in similar contexts (driving) because unbeknownst to me, driving requires the involvement of genitalia in a way that I’d never even considered (how could I, silly little woman that I am?)