I would not do this, because the chassis can act as a shield and as a reference plane of ultra low inductance (compared to a single wire).

But I would not run big currents along the chassis! There's no need to have the generator currents and starter currents running along the chassis. Here, a direct ground connection to battery should improve the situation. But use a connection offering low inductance, especially for the generator!

But even if everything is connected to the chassis, you can drastically improve the situation by paralleling low impedance cables for the high current stuff. Then you have both: The low impedance of cable for the DC components of currents and the low inductance of chassis plane for the higher frequency components.

Once I had to install a car hifi amplifier in the rear of a car. But whenever the driver invoked the brakes a noise could be heard, rather softly but noticeable. Here, such an amplifier providing a quasi symmetrical input was used, where the signal and ground wire were given to the input. Due to difference of source impedances of the both lines, common mode rejection was rather poor though, so the sudden change of voltage drops of brake lamps current running through the chassis could be heard.

So, we strengthened the brake lamps current gound connection to battery and the one of car hifi amplifier by a thick copper cable and solved the problem.

Kai