Here's my Icom IC-706MKIIG mounted on the ashtray. It took a lot of head-scratching to figure out how to mount the remote head, and I wound up making an steel plate that I attached to the ashtray. It's convenient because I can remove the head just by pulling the ashtray out.
Not shown in this photo is the radio itself mounted in the trunk of the car. That RMK remote kit is well worth the price!
Also not shown in this photo is the MFJ-281 speaker mounted with wire hooks made from a coathanger to the headrest supports. It's right behind my head on the headrest so I can hear the radio even while driving with the windows down.
I also have a Heil HS-706 headset, but I prefer to use the hand microphone and speaker. The headset is a very nice piece of gear, but I don't like wearing a headset while driving.
One last note on the IC-706MkIIG - it is one heck of a fine radio for the price. It not only covers HF, VHF, and UHF, is a full-power rig, and all of this in a package the size of a hardback book. The '706 line has been in production for a very long time, and it's a testimony to the fine engineering that went into this radio that it is still an outstanding unit even today. (Postscript: It's a shame they recently raised the price. It appears that this line has reached it's end with the introduction of the IC-7000)