Another thought is to mount it above the glove box liner facing down. Make a plate that bolts under the dash pad that the fuse box mounts too. If i need to mess with a fuse i can just remove the top section of the glove box to access.
Another idea is to put it on the left of the glove box and cut a opening in the glove box
so how is everyone hiding the harness if the fuse box and ecu are in the passenger fender area? Harness doesn't look long enough to run it back inside the car and behind the engine.
The fuse box used is from the late 90s GM trucks with vortec engines. They have a plastic fender well mount bracket that can be modified to fit. I cut the long mounting legs down and build a bracket that bolts to the holes the battery tray mounted to. This allows easy removal of the box for service etc.