Anyone have a good suggestion for an exhaust system that will make my car pop but not have a ridiculously loud note?

 

You can achieve pops when you downshift with a muffler delete

 

Remove the catalytic converters and tune the engine to run rich. The unburned fuel will ignite in the exhaust and cause backfires (technically afterfires). Totally ricey - more of a civic thing - but there's a good way to achieve it.

 

running the engine rich is a great way to destroy your engine .. $$$$$

 

Mine burbles and pops and is only slightly louder than stock in open mode (Varex Muffler). My dual crossover pipe is an expansion chamber so on decompression it draws fresh air into it.
edit: still running cats with no retune.