I personally would either save up some cash, until I could either afford a custom box, or the JL box. I am not a huge fan of either the JL or the trunk enclosure idea. I have heard a few Sols with trunk mounted subs. They sound decent, but the quality just isn't there. In fact, I had heard a single 15 in a sol once, and I thought my 2 10" Kicker solos soundes just as clear. While mine didn't hit as hard, the sound was much better. I have found that the trunk mounted sube just sound muffled. Think about it. There is essentially a firewall between your ears and the subs.