how do you make a exhaust system?

I wanted to make a new exhaust system for my 350z but i didn't know how. It's 1/18 scale.

use aluminum tubing for the tip and long straight sections. and use electrical wiring for the curves perferably 14 or 16 gauge. the tubing could be FOUND at you LOCAL HOBBY SHOP and im pretty sure the wiring could be found at a lowe's or any other hardware store. sorry im not sure wut to use for your muffler(s) cataletic (sp) converter(s) or resonator(s)