While calculating kinetic energy is fun to do, it's not really applicable to personal safety in this case. If I'm going 60mph, then I'm most likely going forward.  If I'm going forward and the remote head is on the dash, then the head unit will tend to go towards the front of the car in a crash, NOT towards me or my passengers.  Personal safety is not an issue here.  Yes, it may fly off and smash against the windshield, getting destroyed in the process, but that's just a financial loss, not bodily.

That said, take a look at the great mounts put out by pro-fit:  http://www.pro-fit-intl.com/

They have a nice line of reasonably priced, well-made mounts.  Vehicle specific, universal, window mounts, etc.  I spoke with one of their mount designers and it turns out he's a ham and is trying to get the company to market to the amateur radio operators more.

I'm using the Ulti-mount for the head unit of my FT-8900, putting right on the dash so it's a short look down from the road to see it.  It also has a swivel ball mount so when my wife's driving, I can turn it towards me in the passenger seat.

For my 706mkii, which I just bought, I think I'm going with "THe Bug" a new product they have.  Both of those products use 3M auto-adhesive tape to stick to the car and this is easily removed if you want to, without residue, yet holds very tightly.

They have a line of "vehicle specific mounts" which will allow you to install without damaging your vehicle but for my grand caravan, it just put the head unit too far away for me.  It might work great for others.  

To see my mount for the FT-8900, you can go to this site:  http://www.pbase.com/lehnherr/ham_radio

Pat
KC0RTQ

Just turn to channel 1 and hit the F key again.  The asterix is an indication that the channel is free, but you can certianly override existing channels.

I also recommend the G4FON software, though I had trouble picking the spaces.  They seemed to be too variable for me to pick up their rhythm.  Still a great program.  Once you've got all the characters learned, check this site out for practices QSOs along with a 10 question quiz:

http://www.aa9pw.com/radio/morse.html

This site got me well prepared for my Element 1, which I passed a week ago with nearly 100% perfect copy.

If it's like my FT-8900, and suspect it is, you push on that slider switch thing, then slide the entire head unit to the....ah....left I think.  One direction or the other anyway.

Here's another vote for the Comet CP-5M.  I've got it mounted on the rear hatch door of my '96 Grand Caravan and it fits great there, and it comes in an NMO mount.  I put either a dual band for day to day driving, or a 40" Maldol EX510 "try-band" (as the package said .  The ex510 works great.  With the dual band, it seems to work the same as my Larsen dual band mag mount, so I don't think you need to worry about hte ground plane.

Also, with the dual band (19" I think), I rarely have to worry about folding it over.  If I do, it's easy to take off or the mount has a simple wing-nut type deal to fold it over.  Just don't open the hatch with it folded over liek that or you bend it up...just ask my wife!

Another thing I should mention is that the extension cables for the FT-8900R are easily made with 6-conductor telephone cable.  You can either make your own to custom length, or buy either extension cable, or modular cable with the extension fitting.  I bought the 7' modular cable with a extension fitting at Walmart to remote the head and it came to all of $7.00

The key is that that cable must be a straight trough, not a cross over. Modular cables are crossovers and need an extension adapter along with using the stock 6" piece.

Another tip.  Add up the cost of all the accessories you'd want and see how the two radios compare.

I was really torn on this same decision...IC-2720H or the FT-8900R.  At Gigaparts the difference is only $25, so price was not part of the equation.  

I've got a tech license, so I can't transmit on 10m, so to me it's a tri-band.  Even so, I didn't really factor the 6m capability into my decision.  I compared them as two dual banders.

I read all they had to say on the reviews of this site and started leaning towards the Yaesu.  When looking at the weak points, the things that really stuck out for me was that the Icom did not have alpha tags and the Yaesu did not have memory groups ( a BIG mistake with 800 memories available!) or PC software available.

The software will come in time, in fact, Yaesu tech support told me RT Systems is done programming, they're just waiting for Yaesu Japan to approve the release.  So it came down to what I wanted more, alpha tags or memory banks.

In the end, I chose alpha tags and bought the FT-8900.  I've gotten excellent audio reports with it, the cross band repeat works great.  I don't know if the Icom does this, but on the yaesu I can set different power levels for each link so that the link to my HT 5w and the link to the world is 50w.  This keeps the duty cycle way down on the rig since I do a lot more listening than I do talking when using it.

The lack of memory banks IS frustrating, to be sure, but it's a easy task of turning the SKIP flag on and off the frequencies as I travel around the state.  Still, it's the ONE thing I don't like abou the rig.

I haven't used it enough to offer my own review on this site, but so far I'm very please.  i sense however, that my situation would be the same had I bought the 2720...I'd love it except for lack of alpha tags.

FT-8900 separation cable is simply 6-conductor telephone extension cable.  You can get the extension cable with the female connector at one end, though I've only found them in 25' lengths...too long for my application.  

What I did was to buy a 7' modular cable, then get the modular cable connector (2 female connectors) to join it to the short cable that comes with the unit.  

You can't just use a modular cable on the FT-8900 because modular cables cross the conductors over, where as the radio needs straight-through cable.  Using one of the extension methods above ensures you're going straight through.  

The third method of course is to make your own cables to custom length.
 
The only think left, then, is to figure out how to mount the remote head.  I'm in the process of looking for a universal cell phone holder that will accomplish this function.

Around here, I hear "monitoring", "listening", just a call sign, and even a "hey, is anyone else out there?".  I understand what they all mean and certainly don't care what a person uses.

I have a '96 Dodge Caravan with the larsen dual band magmount, which is 18" tall.  My garage door is a standard 7' tall.  I hear a bit of a twang as I drive in or out, but not a big deal.

If you do find that your installation is too tall for yoru antenna, you could switch to a Comet B-10, which is only 12" and comes with an NMO mount.

Pat
KC0OXM

There's no volume control, just on or off.

Pat
KC0OXM

I recently emailed Yaesu tech support and they told me they were not aware of anyone working on software for it yet.

Here's another vote for the Larson 2m/70cm mag mount.  I have a 5w HT and consistantly am told from folks how suprised they are that I'm coming into the repeaters so strong based on my power and location.

I just picked up a Workman 2m/70cm Mag mount for $10 at a recent hamfest, but haven't had a chance to compare it to  the larson yet.