How to wire an engine convincingly ?

[Ace-Garageguy]

And for saving money...the majority of wires you'll encounter on street-driven cars in reality are 7, 8, or 9mm diameter (approximately) . Let's say you're doing a '70s muscle car with 8mm wires. 8mm is .315". For 1:25 scale, divide that number by 25. That gives you .0126". Call it .013", and go to the craft store and get .013" beading wire (comes in colors and will hold shapes you put into it).

Enough to do MANY car models for a few bucks.