To be honest, I don't really pursue too many modern mainlines. The increasing amounts of plastic being used in today's $1 cars doesn't instill much anticipation in a hobby where having more kinetic mass often equates to more potential power and speed. But every now & then, those Mattel designers release new models that clearly show that they're keeping traditional gravity racing in mind. Case in point...the 2019 Roborace Robocar.
Despite it's wild, fantasy-like appearance, this is a scale model of a real car. And while it doesn't exactly tip the scales with abundant mass, the metal upper body & fenders appear to be proportioned with some 'dynamic balance' traits. This car also has an extremely low stance with very little frontal area which should yield a low drag coefficient. What this car lacks is Mattel's traditional turned up front end(not a 'loop' car) and smooth sides(not a 'booster' car either), which means this car is a downhill roller....and a potentially efficient one at that!
Comin' at ya'!! ;-)