[8D]Howdy Ya'll,
New to the forum, new to Cruisin' (2003 PT Cruiser Ltd Ed, mine for less than 3 months). I did a simple modification to the stock airbox. Details are here. I'm happy with the results, much better engine sound, acceleration, and response. Here's the page if you want to check it out.
http://home.woh.rr.com/thejamespage/PT.htm
Happy Cruisin' ya'll!