My basic configuration while mobile is "stealth" monitoring. There's no special monitoring antennas on my vehicle. The portable scanners hang from the airvents or are in the beverage cup holders & the mobile 780XLT is in the passenger's seat with an insulated small sanwich/beverage bag giving the scanner the appropriate 45/50 degree angle in order to see it. The portable antenna extends at a 90 degree angle and lays on the dash board. Generally this set up produces highly satisfactory results. The normal problem with noise is primarily from the a/c & heater blower if it's run at a higher speed. I'm still considering using a Am/FM splitter to use the external antenna. I also carry a scanner mobile magnamount type antenna but don't use it on a regular basis. This configuration results in no attention being given to your vehicle when it is parked and/or is on the roadway.