Background
I had a Ram Mount for my Iphone 3G and really enjoyed using it. While Proclip had a fancier looking solution, it did not allow you to customize the mounting the way Ram Mount lets you (literally hundreds of different combination). But I really liked how Proclip had mounts that let you just slide your phone in and out. When I purchased my iPhone 4 I wanted to buy a mount that also had a passthrough cable. Unfortunately they don't make one for the iPhone 4 + OEM bumper, so I was left with the only solution available = Making my own
Parts List
Iphone 4 w OEM bumper holder
http://www.proclipusa.com/brodit-de...case/padded-standard-holder-510178-18231.aspx
Ram Mount iPhone 4 Holder ( you can save money by buying the individual parts from their parts list)
http://www.ram-mount.com/CatalogRes...45066045049051056045065080057085/Default.aspx
TRUE 30 pin Passthrough Cable ( Novapcs on Ebay )
http://cgi.ebay.com/30-PIN-Dock-Ext...904356?pt=PDA_Accessories&hash=item20b81da664
Apple Composite A/V Cable
http://store.apple.com/us/product/MC748ZM/A?fnode=MTY1NDAzOQ&mco=MjAyNDk5ODM
Farenheit 7" Flush Mount LCD
http://www.amazon.com/Farenheit-T7000MHR-7-Headrest-Screen/dp/B000EPKCYA
Tools Needed
Black Radiator Fix epoxy plastic
Vasoline
3m Automix Plastic Epoxy
Bond Glazing putty
Masking Tape
Dremel Tool with Fiberglass cutoff wheels
Step 1 Creating Custom Mount
Carefully drilled and screwed in 4 screws + Nuts
Using A dremeled I removed all the extra screw/nut/Labeling that was on the Ram Mount Using a Fiberglass Dremel Cutoff Wheel
Step 2: Molding 30 pin adapter to Holder
In order to avoid having to plug in a cable in and out it would need to be molded in and glued to the adapter. After researching it turns out using a pliable epoxy would be better to start off with vs a liquid epoxy like JB weld. The radiator stuff looks like this
Best method I found was
1) Put a little bit of Vasoline on the mount and outside of iPhone bumper first so nothing sticks
2) slide iphone down into bumper all the way
3) Using a dremel you will probably have to sand off some plastic so that the extra large AV plug fits into the iphone with the Bumper on it. No need to be neat, this will all be covered up
4) Once the AV Plug fits plug it into the iphone.
5) Mix the putty and then you will have only a few minutes to mold it around the iphone/holder/cable
6) Let it dry for a bit, but before it hardens you can cut off any extra material before it fully hardens
7) Mix the 3M automix and apply. You will probably want to do 3+ layers to fill in all the depressions. Let it dry, sand till flat, repeat until it looks good
8) Do the same thing for the mount holes, this takes one layer and pretty easy to sand to make it look better
9) Once you get your General shape use spot putty for the tiny holes
10) Sand, and mas off areas you don't want to paint ( bad idea to use nurses tape, it leaves a residue, I ran out of blue painters tape)
11) Paint black.
12) Find how to mount it and then plug in your av cable to your monitor
From this picture you can see I used a zip tie to get the cable out of the way + still allow the mount to rotate, and I cut away some material in my dash to allow the cable to route behind my center console
13) I really Recommend Paying for GPS Drive as a pretty Nice way to use the secondary 7" screen ( besides playing videos, etc)
Questions are welcomed !