We all have to have second vehicles next to our stangs. Mine happens to be a 97 cavalier. Good reliable car. Anywho, I had some of the same aspirations as you do for your 2000. I found a very good website that beleive it or not specializes in cavaliers.
www.rksport.com They have everything from exhausts to intakes to nitrous kits. very in depth site, you can anything you could imagine from there for your cavalier. when you go there, they have an exhaust that has dual tipped dual exhaust. In actuality, it is the one pipe back to the muffler, and then four pipes out, two to each side. sounds f-ing mean, and adds a little punch too. Another big one is the K&N. I ripped out the stock box, and replaced it with a conical K&N. Car sounds deep, and added more punch than the exhaust. hope this helps.
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Warmed over 302,
Edelbrock Carb, MSD, Accel, t-5 w/ frpp flywheel & clutch, Hurst shifter, traction bars, ds safety loop, subframes, 3.08 posi, shorties, H, and Flows. Same setup w/ auto netted a 12.54 @ 110.90
in a 300 lbs heavier car.
Can't wait till Spring for E-town.
1981 GT