Just got the iGrip with the cig light mount. It's an excellent product. It will seat very securely in the holder. You just need to be aware that the two pieces, the stem and the holder are fastened by and up and down motion and the clip takes some pressure to slide in.
There are two clips that sit underneath the holder's grip that slide left and right. They are easily positioned to allow for a connection under the iPhone which I have to allow both a charge and steering controls for use of the iPod on my 99 Acura TL.
The stem can twist which is very good but the unit operates both very flexible and solid. It would be easy to remove the iGrip and use it in multiple vehicles.
Last it has a release button that will open the width of the grip to allow easy removal of the iPhone. The only downside is that it's not quite wide enough to use easily when the iPhone is paired with my Casemate case. I wish it had just a bit more width so I could leave the case on. It'll fit but not easily.
Think they adopted this for older phones and now the iPhone. It's so close to being perfect with a case and iPhone if they just gave it a millimeter more width at maximum.
For the money it's tough to beat. And I much prefer this option to any windshield mounts.
On the Acura TL, there are controls that control the volume and can change the song right on the steering wheel. I recently installed a unit from Icarkits that work with the phone and the steering controls and also provides a charge to the phone.
but would much prefer the looks and size of the custom fit version. The 3g is less than 1mm thicker, it seems strange that the small amount of difference would be enough to make the mount not work. Anyone have a 3g iPhone and this mount that could try it and explain why it won't. Would it be possible to modify the mount to make it work?