There’s a gap under my aftermarket stereo in the Tacoma, a general-purpose pocket which I haven’t found really useful. What I didn’t have is a cell phone holder.
I bought one that was designed to wedge into a CD player slot, thinking it would wedge into the pocket, and that worked for a while, but wasn’t really secure.
I liked the metal grasping mechanism, but not the attachment, so I designed and 3d printed a wedging clamp that fit into the pocket and expanded when tightened. Then made a bit that attached to the clamp and allowed the phone holder to screw into it.
The mechanism consists of two sloped blocks with holes that allow a 5/16″ bolt to run through. The back block has a recessed area to capture the nut.
As the bolt is tightened, it pulls the top block up the ramp, allowing the mechanism to clamp firmly between a 30-39mm gap.
The vertical slots in the front face of the top block are keys to prevent the phone mounting bit from rotating.
The bolt passes through the phone mount adapter, holding it securely, the vertical keys allow it to shift up and down to stay square to the bolt. The phone mount screws in to the bottom of this block. The length is intended to keep the block far back enough that most of the clamping force is under the radio, instead of just on the thin plastic.
This is a much more secure solution for holding my phone, and it seems to be holding up well after a week of use. I may have to reprint it in ASA instead of PLA next summer, as PLA plastics can soften up in summer car temperatures.
If you’re interested in printing one, here are the STLs: