I was looking over some of my cars and I think I discovered what the 1970 Hot Wheels Tribaby might have been designed after.
I believe it was loosely designed after a unsuccessful prototype car the Monteverdi Hai 450 SS. It was after looking over an old 1973 Matchbox version that made the Tribaby stick out.
The similarities are there at least in the front and a bit of the side window design
Not sure if Larry Wood got the inspiration from the real car or just a coincidence.