My car is all steel - but I have a 2 awg cable from the battery to the engine and three of the woven cables from the engine to the body, one very wide and 2 fairly narrow. Then there are the usual wiring grounds......... As far as the woven cable being a poor choice - current flows along the outside of each strand and there being many in that woven cable, will do as good a job. Quite frankly, the only ones I've ever seen corroded are those older, pre electronic cars that used them for battery grounds - and the other being often just as bad - and you can't say positive as Ford used a positive ground until they went to 12 volts in '56.