Thanks for the feedback on our products - we're glad you're happy with the upgrade! I should note that you may feel the bass is overwhelming the interior speakers due to the gain settings being too high on the subwoofer amplifier. I would recommend turning the gain down a bit on your amplifier (call or e-mail if you need help with this) to get a more natural blend with the interior speakers.
After making these tuning adjustmetns, if and when you decide you're ready to move forward with the amplifier upgrade, here's what I would recommend paired with what you already have:
http://www.bavariansoundwerks.com/pr...I=435/_cid=164
2 x
http://www.bavariansoundwerks.com/pr...I=480/_cid=285
http://www.bavariansoundwerks.com/pr...I=452/_cid=285
http://www.bavariansoundwerks.com/pr...I=360/_cid=285
That's the amplifier + all the required wiring and installation components to integrate with your factory head unit.
By the way, would you mind if we used your review of the products on our website?