FiberGlass & MDF Truck Box

Ok... i am going to make a fiberglass enclosure for a 10" sub for my Dakota reg Cab.  I am going to use the measurements for a standard 10" Truck Box.  I plan on making the side peices and using 1/4 Dowels to make the frame and then covering it in fleece and FG'ing it. 

Do you think this will work out alright?  Will the 1/4 dowels hold when i pull the flece tight?  I want the rounded corners and if i have to i can just use the fleece which i think will give me a REALLY rounded corner (coming over the top of the Sub Ring and going to the back) OR jsut round off some MDF. 

Am I going about this all wrong?  Can i make my MDF Frame... then FG it like my diagram is?  Any suggestions or Modifications?  Also... once im done FG'ing it... can i drill into the side bottoms to attach brackets to attach it to my truck?  Or is there a better way to attach it?  Thanks for all the help!

http://www.porter-designs.com/box.GIF">

Didnt seem to work...

Trying to get the diagram up... maybe this will work.. if not its here : http://www.porter-designs.com/box.GIF

It will depends on how tight you stretch the fleece before the dowels will bend. but if they are not to long you should not have much bend to the dowels.