The 919 Tribute is actually pretty close to what an "unrestricted" F1 car would look like. Fully enclosed bodywork (which used to be legal in F1 back in the 50'

The 919 Tribute is actually pretty close to what an "unrestricted" F1 car would look like. Fully enclosed bodywork (which used to be legal in F1 back in the 50's), an unrestricted hybrid system, AWD, and active aero + suspension. In order for an F1 car to beat this unrestricted LMP1 design it would have to wind up looking more like the LMP1 design than the F1 car it started as.