As I continue to read and learn about my 2013 Brabus I was surprised the door speakers had so much low end and then I read that some models came with a subwoofer under the seat. I didn't think mine had one even though it has the touchscreen navigation because I don't have any pillar mounted tweeters. Upon further inspection, I noticed a plastic box with wires leading to it under the driver's seat. When I fired up the CD player and went into audio set up I noticed the option - X-Bass - It was set very low so little by little I raised it up while placing my hand on the box under the seat, and yep a subwoofer. I have to admit that I was pleasantly surprised and also the fact I just saved about $300.00 for a subwoofer I was looking at buying.