skman:
Umm...the tip I bought was about $20 at Auto Zone or Advanced auto parts. The 3.5" had a bigger inlet to it and it fit right over the stock tip, but the smaller tips wouldn't fit. The little curve in our back bumpers where the exhaust comes out is 4" in diameter, so 3.5" tip actually looks pretty good, it seems to fit right in there. There are three clamps for the tip I bought that hold it onto the muffler pipe, and ya have to tighten them evenly to keep the tip straight. I kinda tightened one too much so my tip comes out a little sideways, but I'm just to lazy to fix it.
Now let me see if I can post some pics....