Run big pipes on a straight-through muffler and no cat. You'll get the pops and snarls. Thing is, SRT-4 run a different firing order from Hondas, so you get a fundamental difference in the sound. Hondas are 1234, SRT-4's and a lot of other 4-bangers are something like 1324.
Maybe you could fake it with custom headers, adjusting the length of the runners and where they join into the main flow, but that's a rediculous amount of money to spend on R&D just to sound like a Neon.
Just go for a good Honda sound: the F1-like scream at high rpm's. Most other motors don't have that.