If you want it removable you could use a rubber gasket material (possibly get it at an auto store by the sheet). I would also use something like stainless allen bolts with washers to help prevent cracking, pluse it would look nice. You could countersink a threaded sleve, kinda like drywall anchors but ones that would hold up in wood.
2006 Jeep Liberty
Adire Audio 15" Brahma running off Cadence A7hc, Clarion hu, MB Quart 6.5s and 5.25s running off old school Punch 800a4
146+db @ 38hz with 1200w and a single 15"
Lv = [(14630000 x R^2) / (Fb^2 x Vb)] - 1.463R
*Vb = vol. in cu"
**R = sq.rt. A / Pi (for square/slot port)