I don't have any pics, but I have an audiocontrol EQ under my HU. The shop that installed it used some sort of 90 degree shaped fasteners with two holes in it. One side is screwed into the eq and the other is screwed in under the dash.

vinny "2000 T-RED SVT"
Mods:
kkm
sho shop off road y-pipe
Audio:
Alpine CDM 7874
Audio Control 4.1 EQ/Line driver
Mb quart rsb 215 comp.
Mb quart rsc 216 comp.
blueprint 1001 sub
2 Phoenix Gold qx2180 amps