best place on the back wall to mount an amp?

i bought 2 new 10" audiobahn subs for my single cab sonoma, and i am thinkin of goin on a gettin the audiobahn amp but i need a place to mount it. anybody know if that plastic peice right under the window would hold and amp?...it seems pretty sturdy...here is a picture of the peice i am refering to.

ignore the rockfords, i took this pic to get a general idea a while back