Ground point under dash?

[Matt's4Runner]

Any suggestions - pics would be preferable?

I have a second hand Prodigy controller mounted on a cup holder insert. Need to ground somewhere. Also, I run the wiring from the (hard to access) built-in plug to the cup holder mounted controller over the steering column to avoid interfering with knee air bag. Is there a problem anyone can foresee?

 

[Jeremy556]

Most of the mounting bolts under the dash are grounded.

I have mine routed to the same area, but mounted in the lower panel. Just make sure it clears the parking brake and steering mechanisms.