Very close in parallel might cause interference, but the problem will be worse on the CB than on VHF ham. Some space is better than nothing. Do what you can, the important thing is get 'er done. Good coax would help, too, which is the problem with most CB. The shield weave is crap, just crap, that they include with off the shelf stuff.
'91 Pickup - Imelda
'08 Tacoma TRD - Donna