I've been making 3D printed chassis since 2011 (and designing parts using the process for more than 10 years longer), I use Nylon made by the SLS (laser sinter) process which is incredibly tough and very resilient to a motor's heat. But new materials and processes are coming out all the time, it's an interesting thing to see develop.
I've recently done a new front end for the popular PCS32 chassis, it's got steering but as there's no tooling needed I've been able to design four different widths to suit almost any car. As builders use different diameter wheels I've also made the guide blade holder to sit at different heights.
The whole thing weighs a little less than a solid front axle; the nylon is very light and the stub axles are aircraft grade aluminum



Will it win you a race? I've no idea as I'm not a racer, but it does make things look more realistic and wouldn't have been economically possible without 3D printing.