people put mongoose etc exhaust systems on their cossy's and RST's not to make em 'loud as fook' its for performance increase.
cutting out the midbox and shitty welding some slightly wonky tube in its place makes it louder but probably will loose you power and sound pants.

lets see some pics of this fiesta ?? not knocking it if your happy, but for example my mk1 fiesta, doesnt sound like a v8. EVER and i certainly wouldnt say it has the best exhaust note ever! running it on a manifold and downpipe it just sounds like fart. and with silencer just a tappety old fiesta.