Mobile Antennas and mounts.

Mobile antennas.
Mobile antennas come in different sizes and many different mounting types. The type you chose will depend upon whether you want a small, tidy one or one that works well but may be rather large.
The type of mounting will depend upon the vehicle you use and how you have to mount it. Although some small antennas come complete with a magnetic base, most will come without a base so that you can select any combination of antenna and mounting type.
There have also been telescopic CB types disguised as normal car radio antennas and special splitter boxes available to run both the CB and car radio from it.
BEWARE: Some may not withstand high speeds - they may snap or fly off the vehicle if used at high speeds.

Magnetic mounts.
These stick onto the metal of a vehicle (the roof is best), and have the advantage that you do not need to drill holes in the vehicle.

These are easily removed, so should not be left on when the vehicle is unattended - these have often been stolen. Also, beware of scratching the paint work, as this does happen with these.

Bolt mounts.
These need a hole to be drilled to fit them, but the direct connection to the metal of the vehicle body gives better results than a magnetic mount. The one shown on the right has a mounting that allows the angle of the antenna to be adjusted to allow for mounting on a non-horizontal surface.
If you fit one of these, you should be careful where you drill the hole and make sure that the top is water tight.

Gutter mounts.
Possibly a bit difficult with modern cars, but these would clamp to the gutter of a car roof. To connect to the car body, some paint should be scratched away where the screws clamp it. They do allow a direct connection to the body, but without drilling a hole.

Mirror mount.
Useful for trucks, where the cab body is often fibreglass. The mirror provides the required connection to the metal of the vehicle.

Window mount.
Some antennas were made with sticky pads for sticking on the window. As the antenna is designed to work this way, the mount was not available on it's own - just with an antenna. These were useful for fibreglass cars such as the Reliants.

Boot mount.
This mount fits to the edge of the boot door.
There are also similar mounts available for the rear door of Estate cars and Hatchbacks.