hi all ive got the stock premium sound system on my au xr8 and want something louder but want to keep it looking as stock as possible ive decided to upgrade amp back speakers and the 8 inch sub thats on the parcel shelf. does anyboy know any good free air 8" subs on the market

To be honest, there is an 8" Sub at Jaycar. This costs $40, and handles over 100wrms. I have seen this used as an upgrade for those crappy paper cones used in really old home stereos, and I'm sure it would work fairly well. Used in a small ported box, this shook the crap out of a honda civic hatch so it couldn't be too bad.

If you're keen, maybe you could figure out how to mount pioneer's free-air 10" sub, in the same location. Would require a decent baffle, but with two 10" wooden rings, this would be easy. Depends on how creative you are. I've seen these subs selling for less that $80

unfortunately, afaik there's no decent 8" IB/Freeair subs still available..... best bet would be to track down a 8" midbass driver from total recoil, hertz, etc

until i had the cash to upgrade the premium system in my EL al i did was buy a 10" JL sub in a sealed box and connected it to the existing amp, the factory sub from memory was an 6 ohm impedance. so the 4 ohm JL sub worked alot better. made the mirrors shake even tho it was only about 100watts of power from the amp.