This post is ancient, but I just came across it and wanted to add some of my notes to it.

I installed a permanent mounted antenna in the roof of my VX. I'm using 2m/70cm ham antennas instead of 11m CB antennas, so the sizes are different. Still, most of the idea still holds. For best results, use quality parts and mount the antenna in the center of a mass of metal with a clear 'view' to the horizon.

Someone mentioned an NMO mount. This is a great idea, because it also allows you to swap out antennas when you want. So, you could have a coil-loaded short antenna for day-to-day driving, and swap it for a monster whip antenna when you're playing in the hills.

I'm not sure how that will work for CB antennas, though. They are typically longer, so roof-mount might not be a possibility at all for you. You'll probably have to mount it lower, and your performace will suffer somewhat because of it. You might need to look into some sort of flexible mounting to limit damage if you hit something. (And a tennis ball. ) My antenna is about the same height as the stock radio antenna, so it is relatively safe. I've got a better (longer!) antenna, but I couldn't park in my own garage if I left it installed.

Make sure you remove some paint around the edgest of the hole you drill, to allow your antenna to ground to the roof well.

Putting your antenna near the stock radio antenna would be nice, but keep in mind the ridges of the roof. They are too narrow to hold an NMO. This makes most of the roof totally off-limits. Instead, I put mine just in front of where the center ridge ends -- the rear-center of the flat part of the roof. This lines up just forward of the dome light, which makes it really easy to run cables. They follow the dome light cables towards the passenger door and down the A-pillar.

There are also trunk-lip antennas (which you could also put on your hood) or antennas that go on the luggage rack. The license plate frame isn't a bad idea, either. Check out the ham radio field for other ideas -- amateur radio "10-meter" antennas are really close to CB antennas, so the technology is comparable. If you've got Tone's hitch installed, the receiver hitch antenna mount might fit your needs.

I used an NMO mount from Larsen. Keep in mind that the difference between cell phones (at 900-1800MHz) and CB (at 27MHz) is large enough that the NMO connectors aren't necessarily interchangable. That is, the mount for a cell antenna won't perform as well as a mount for a CB antenna.

Larsen also makes antennas, but I went with Diamond Antenna because they had one that was not much longer than the stock radio antenna. It looked nicer. If I want a better-performing antenna (which is longer and uglier), I can just unscrew one and screw on the other.

Spend money on a good antenna even if you aren't ready to drill holes in your VX. Get a mag-mount with an NMO on it, and it will work adequately until you get up the guts to install a permanent NMO mount. It will also give you an option if you want to use your radio in a different car.

I did my shopping at Ham Radio Outlet, but you might also be able to pick up something at Amateur Electronic Supply. Ham operators are probably going to look down upon you for using a lowly CB, but they know their products, well. For example, this site has a LOT to say about the relative quality of various antenna mounts.