Mis-posted - sorry!!
So I have done searches all over and it seems that so many here made outstanding subwoofer(s) installations. I thought it would be great to have all the info needed for those who utilized the stock location! and have made a custom box! to fit in that area!... It is very tricky for both building the right box and have the right sound performance...maybe we can all learn from each other.... so here it goes this is what I have...

Box (Ext Vol): 18X14X7.5 (Ext Vol) - Barely fit in that location!!
Box (Int Vol) : 16.5X12.5X6 (Int Vol) - 0.6cf
Wood: 3/4MDF, wood glue etc.
Sub:Rockford Z3410 (sub requires 0.75cf)
Amp: Rockford 150S bridged
Dynamat: No
Rattling: Very little from the stock metal plate
Sound quality: Punchy but poor on the low end fill, was improved significantly with the box in the hatch... (both punchy and low end...)