It isn't so much you getting into the electronics (albeit that happens), but the electronics getting into you.
Like all modern Hondas (and a lot of others too), there is a common data buss which carries signals to the various electronic devices. The data rates are: K-line:10.4 kbps; B-CAB:33.33 kbps; and the F-CAN:500 kbps. These data lines run throughout the vehicle, and are coincident to the running of the fuel pump. It in turn, runs when the ignition is first turned on, any time the engine is running, and runs after you turn off the ignition and there is still oil pressure. This fact leads a lot of folks (including me), to come to the conclusion it is the fuel pump causing the egress. It isn't.
The harmonics extend well into the VHF range, and can effect almost any mode of transmission including FM. One of the biggest "leak" points is the area where the AM/FM, Navi, and XM radio antennas are located (at the rear of the vehicle's roof).
This behooves you to mount the antenna away from this area to minimize both ingress and egress. On an MTX, the best spot is the front of the vehicle. I have to assume you're not a hole driller, so an angle bracket is probably your best bet.
As for the radio, the MTX may or may not have a power operated right seat (depends on trim level), and if it doesn't, this is the best place to mount the body of the radio. As for the head, you might look at the Photo Gallery on my web site, and look at the Other Installs album. You just might get a few ideas.