To be pedantic it's a Reliant Robin (Reliant being the brand).

They actually are pretty stable vehicles, contrary to their reputation. For that clip you linked to it's like everything in Top Gear - staged for TV[0].

[0] https://www.roadandtrack.com/car-culture/entertainment/news/...

They are if you (like the Morgan) put the two wheels at the front.

These days, I believe all auto manufacturers that make three wheel cars (peugeot, etc.) .. make them with two wheels in the front.

I believe the majority of three wheel motorcycles are also made this way now as well.

Mr Bean's arch-enemy's car

Mr Bean drove a Mini - he famously drove it from an arm chair on top in one episode. Are you thinking of the Trotter brothers?