Free-Air installs won't sound good for a hatch as u can't exactly seal off front and back waves in a hatch, unless, of course, you make a permanent seal.
There's quite a few 10" subwoofers that only need a small 0.5cuft box, check around, a 10" would be enough for most small hatches like the MyVI
i got fren do the Myvi ICE setting b4... and the owner is satisfy with the setup...
maybe u can try to tell the budget and ask for the quotation?... anything, u can try to PM me lor... i can bring u to my fren and show u... if u need a demo, he can try to arrange the Myvi to show u, maybe...
mean install without box & use car boot as enclosure.. this method only for sedan car.. not for aeroback/hacthback.. Normally ppl use sub required bigger enclosure like >3.0 ft cubic