Thank you very much
I have been looking into getting two 10 in. subs for my 335i and placing them in the trunk. I initially wanted to find out about the stock subs and upgrading them. Your PDF just helped me decide on what I want to do before spending more money yet.. The installation instructions are clear. Your response to 335 Trojan about your sound improvement also provided some great information and the opinion on quality was what I have been trying to find out. Thanks again for the post. I'll try these subs now.