I purchased a JL Audio stealthbox from Sound Advise for my Volks W Jetta. The sub it came with (single 4 ohm) was incompatible with my amp. I replaced it with a dual 4ohm. They will allow me to switch up the single 4 ohm for a dual 2 or dual 4. I will let the buyer choose. $140 shipped. Send me an e mail at eviljin@bellsouth.net