What Spoiler Tip is best for my car?

So my friend owns a 5 speed Mercury Cougar. This is the slowest car in the world. I never thought it would be cool. But the other night, he rolled up and revved his engine and it sounded AMAZING. I asked him what he did to it and he said he just put a spoiler tip on it, nothing else. But he won't tell us what tip it is. I own a Volvo s60 and would love for it to sound cool for less. Anybody know of any great spoiler tips that will make my car sound fast and smooth? (Not rough as if i bought an Apexi muffler or something) All suggestions are greatly appreciated. Thank you.