I installed a Yaesu FT-1900R in my truck yesterday. It was quite the experience.
The first part was figuring out where the transceiver would go. After much looking and taking apart half the interior of the truck, I figured I would remove the ashtray (since I don't smoke, it was a coin tray). I had to modify the ash tray holder and the radio mount to hold the radio mount from the sides.
The second part was actually installing the rig. Getting the antenna wire and the power leads through the firewall sucked - I ultimately pulled the grommet for the radio antenna, cut it a little (from the edge and a + in the center), got the leads through it, got it back in, and caulked the heck out of it with silicone caulk. Fortunately, with its location, I would have to be driving through a monsoon before it would leak even if I didn't caulk it.
After all this, I placed the antenna on the hood (its a magnet mount for now, but my next change is going to be a hood mount), and went to a local park to test things out. I did hear a little bit of engine noise (I'll have to put a filter in the power line), but I was able to hear quite well and even (somehow) picked up some guys talking about locations in California on 146.5 Mhz... it was S9.