Take for example the below Toyota 86 and Subaru BRZ. Similar looking cars with almost no similarities under the skin.
That 86 is a mother chassis car, carbon fiber tub with front and rear tube subframes. Link to an excellent article on its development:
Meanwhile, the BRZ is built from a production chassis powered by a WRC derived EJ20. To compensate for the production derived chassis the BRZ is allowed somewhat unlimited aero development.
What I didn’t say about the 86? It’s powered by a ~500hp Nissan VK45DE, because that makes perfect sense right?
Not crazy enough for you? Here’s a GT300 Prius:
The GT300 Prius uses the hybrid components from a regular production car... paired with the 3.4L V8 from the Toyota LMP1 car. Unfortunately it’s on its way out.
Also on the “Mother Chassis” are this Evora and Toyota Mark X:
Added to the mix are the full mix of global GT3 cars:
Here’s the replay from the 300km of Suzuka, NISMO has great live coverage available on YouTube, posts full replays of every race after they end, and has a back catalog going back several years.
It’s just damn good racing with a diverse field, and GT500 cars blasting through the field at near LMP1 speeds.