If you wanted to you could remove the plastic cover and use trailer tape (adhesive tar with a aluminum outside) to line the cover this may help absorb the efi. the easest way to remove it is to move the pass. seat all the way back and (after removing the rear seat cover, pull at the bottom) and remove the armrest it is only 4 screws 2 under the felt inside and two under the wood pull up trim. peel the cover off the left side and you'll see it white plastic cover. you are going to need 3 seat clips before you start. cause you'll destory the old ones by pulling off the rear seat cover. the trialer tape may not work. the seat sensor is located in the foam of the seat this may be the part that picks up the efi. you seem to know alot about the curcuit so you know it is designed to detect a small person and disable the pass airbag. one suggestion may be to unplug the sensor all together from the opds unit. The unit shouldn't see a open but rathier no sitting in the seat. I don't think your radio will affect the curcuit since i haven't heard of cell phones, nextel nor cb's from truck drivers affecting the curcuit.