Antenna

OEM Antenna
The OEM antenna is an 11" mast on top of a small amplifier module.  The amplifier is why there is a power cable also running to the antenna.  It appears to have been sourced from Fuba.

Modifications
If you've already added Lift, you might have noticed that your Vehicross doesn't fit in the garage anymore... You may be able to resolve this by swapping out the 11" mast for a shorter one. You may be able to attach almost any 5mm screw base mast, but the weather-resistant flange around it will fit much better with specific designs.

Our antenna system is the same as used on a number of Volkswagen models, like the Bora / Jetta Mk4 (1998-2004), Golf Mk4 (1998-2005 1st half), Passat B5 (1998-2000), Passat B5.5 (2001-2005), Polo Mk4 9N (2002-2005). Pretend you own one of these, and search.

At the very least, the Volkswagen 9 inch Roof Mast Stubby Whip Antenna for Jetta Mk4 Golf Mk4 Passat B5 B5.5 Polo Mk4 9N fits well, and was enough to get the antenna under one garage. A 3.7" appears to be available as well.

There are also some REALLY tiny antennas, but they appear to simply be a chunk of billet and are not electrically sound. They won't work well as an antenna, but for some people that may not matter.

CB/HAM
One owner put a Motorola mount just forward of the cab light and ran the cable through the headliner, down the A-pillar, and into the center console. It worked well, but conflicts with a basket on the roof rack.

CB antennas are longer, and should probably be more conventionally mounted on rear bumper. Note that, since you don't have a steel bumper, you won't have the groundplane you might need.