I recently picked up an M5 and am in the process of selling my SLK230. I had a custom subwoofer enclosure fabricated some time ago that I have no use for now. I will give it away to anyone who wants it. I would PREFER that someone picks it up, but if you're willing to pay to ship it, I would be happy to give you a quote as my friend owns a UPS Store. As you can see, this enclosure goes in the trunk. You obviously have to remove your spare tire for this to fit (although I have no idea why that would be a problem as I have no idea who would seriously consider putting that spare on the car). It does not interfere with top operation and actually sounded QUITE good in the SLK even with the top down. Here are a couple pics of the new ride and the enclosure in the car.
