Add exhaust materials like titanium and stainless steel
How many factory car models can you mention that uses those materials?
But I agree, it would add something.
Mainly to the prestige stat, and maybe lower the service cost. They really don’t rust.
Super cars use titanium exhausts like the Ford GT, Porsche 911 GT2 RS, and more.
These more advanced materials would weigh less, but they would also have a higher material cost, as well as requiring more production units and engineering time.
On the topic of materials, i would loe to have glass as a material which would help with making neons, shifter lights on racecars etc.