I have a Uniden Washington out in the shop with a base station antenna. It easily talks to other base stations 25-30 miles away, and I have made quite a few skip contacts with it also. An AM-only CB is fine for a mobile, but if you really want to start making more contacts I suggest getting a unit with SSB and setting up a base station at home.
I haven't played with the CB's much since I got my ham ticket, but I still get on once in a while. Most of the time I talk on the Kenwood 2 meter radio in my Expedition.
What kind of base antenna are you using? I've been thinking of a eBay dipole in a tree or maybe in the Attic of my garage.
You can paint the fiberglass vertical antennas so they are less noticeable. A dipole will work also, but you will have to play with it to get it setup properly.
Would having a dipole in the Attic affect it's performance greatly? I've been reading up on them and other antennas alot lately. Seems reviews are all over the place. I guess environmental conditions plays a pretty big role in antenna performance.
The tuning may be off from interaction with anything else in the attic. There will be attenution through wood, shingles, etc.
Most CB'ers use a vertical antenna. Your attic dipole will likely be horizontal. Broadside, it will radiate a horizontally polarized wave, moving more towrd vertical polarization off the ends. With ground wave propagation, there can be up to 20 dB of cross polarization loss between a vertical and horizontal antenna, but in practice there are a whole lot of things that can affect this. Vertical or horizontal polarization is irrelevant to signals coming off the ionosphere - it jumbles the polarization.
There are RF exposure limits. If you are running legal CB power, that likely would not be an issue even with an attic mount antena. If you are using illegal power, as many CB'ers do, you may want to do the math.
An attic antenna is lots better than no antenna at all.