Customer states the radio has a faint background static. No audio source is present. An audio source with low volume is being played. The vehicle is utilizing hill-hold. Vehicles with hill-hold (PR No. UG1 or UG4) and Audi Navigation Plus (PR No. 7Q2) are affected. There is electromagnetic interference between the ESP power supply and the wires for the radio. This proximity caused interference to enter the audio lines for the radio, causing the static.