Thought I'd post the RAM mount system I used to get a nice iPhone holder placed "just right" behind the gear-shifter.
The RAM-Mounts have holders for just about anything, and the thing I liked about this one was the easy mounting (just undo a floor bolt holding the seat and place the "boot/foot" between the bolt and the floor. I needed a washer, and drilled a coin as I had none available. There is an aluminium bar you need to bend to get it in the position you want. It's fairly heavy to do with only your hands, so a vice is recommended. The nice thing about the kit is it does not require any drilling, or gluing/taping. Easily removable again!
Of course my better half immediately demanded the removal of the offending mount as it chafed her left thigh... so I'm going to order a longer alu-bar and bend it along a different route.
Here are the images, sorry about the blurry pictures, it was dark in the garage.
Here you see the boot/foot attached to the seat bolt on the floor
This is the alu-tubing used inside the plastic wrap, easy to bend with a little effort and a vice or similar. Or you can just lean on it agains an edge/corner.
There are of course a lot of positions you can place the holder in using this system. I chose right behind the gear lever, and the gps reception was very good even with the dash above the iPhone. The sideways positioning is optional, it works equally well in a vertical position.