UHF Bleed-through

I recently had an icom 880h mounted under my passenger seat. I since moved my radio to the rear cargo tray area. Before I moved the radio I was not having any interference at all. Since the install however, whenever I key up on 70cm, my speakers make a popping noise and a steady, dull, loud hum comes through my stereo speakers. I do have a subwoofer that is somewhat close to my antenna (never caused issues before) however the coax runs a few inches closer to the sub (oem sub). I used to have the radio ground at the back of the vehicle, but moved it I the front near where it was grounded before thinking that was the issue. I also ran a ground from the radio chassis to the back. Still have the same problem. Any tips/suggestions?