OK - for now you have a shiny black Z3 that's all show & no go. I see blacked out tails,a nice clean front end and interior, a trunk totally full of subs and ampage and word of big mufflers and a cold air intake. For a 2.0L engine - you have few options if you are looking for increased power besides forced induction or "FI" which on fact does mean supercharging or turbocharging the car. "NA" means "naturally aspirated" - that the engine is basically getting air on its own as designed, without and device forcing extra air into it via FI for additional power.
To get more power, you can either do some expensive modifications to your own engine with only modest power gains like new headers or boing it out bigger, or go FI. One other solution is to swap out your 2.0L engine for a bigger more powerful one that is NA like one from a 3.0L Z3 or perhaps a Z3-///M or ///M3's S54 3.2L engine. The cost effective answer is to add a supercharger - which uses incoming gases and forces them into your exisitng engine to increase it's power. This can be done with a nicely tuned chip for your specific engine that helps preserve drivability and the life of your engine. A turbo is more expensive, gets more power, and uses the outgoing gases from your engine being forced back onto it to boost power (this is why FI cars are said to have "boost"). Again- a supercharger is more amenable to your BMW and it's linear power curve and is less $$. If you do employ FI though - you will need to upgrade your brakes, suspension and likely your clutch kit to match so we are talking about an investment here - it just depends how badly you want more power and how much. It sounds and looks to me like you want a noticeable power gain you can really feel in the seat of your pants. If so - it means one of the options I listed. Again, depending on your budget and needs - you have to choose the best fit for you and your Z3. I went with a Supercharger as you can see and liked it a lot, although now I would go for a turbo as my tastes have changed to the more expensive and needs to the mote powerful. In a perfect world I would take the engine out of a 2001 or 2002 Z3-///M and supercharge it. Far more reasonably & keeping plenty of life in your car - I'd get a Dinan supercharger or one tro Active Autowerks. I'd try and stay away from VF Engineering (that's what's in mine - look up other threads on Bimmerwerkz or that discussion. I hope this helps you. Best of luck and enjoy your beautiful car!
hnoes
