Anyone ever install or own a BMW Z4 with subwoofers in the trunk?

I have on 04' Z4 and would love to put some subs in the trunk to fill out the sound. I have never put a system in a convertible and am worried it will not produce good sound with the top up or down. The factory system pretty much rocks as is, but on certain songs with lower bass tracks the factory woofers can't produce. I have looked at both end of the spectums as far as what to put in: was looking at 2 10 inch JL audio W6 V2, with amps, crossovers, etc. I have also looked at just throwing in a 10' amplified bazooka tube. Any thoughts?Anyone ever install or own a BMW Z4 with subwoofers in the trunk?Hey man forget the amp tube. All you need for a car like that is 1 10" t1 sub in a 3 foot box , with a 700 watt amp. Thats sure to be setting off car alarms as you roll by.