I would love to see some well fit enclosures which look nearly stock, provide a little boom and don't sacrifice what little space is behind the seat. I currently have a box which was made for my Subaru and it takes up nearly the entire rear of the car.
Are you talking about custom printed boxes? I am currently an associate with the Custom printing boxes firm in the USA here in Texas People love to have their own custom product boxes for their products.
I am doing one, which i saw on Russian site or video. Stock looking, amp on boot left side and sideways. Sub (10") uses spare wheels innard cavity plus the 2" rise for the box. Luckily i have a raised plexiglass top on my 5 channel amp so it levels with the box. So the boot is completely flush, almost stock looking and stealth. Spare wheel can be accessed raising the box.
Put a fine grill for sub, then only the amp is visible trough its top size window. Box size is about 36 to 40 Liters. Put all my old gear to this and have semi active 3-way front (dome mids & tweets on mirror covers, stealth) 6" midbass on silenced (deadmat+sealed) doors and Alpine dsp head unit.