This car is famous for corroded light sockets, not just failed bulbs. Ck again with the emer. flasher on. Ones that are dimmer or blink too fast are the sockets to check for rust. The radio noise if it is a BOSE system are failing amps. My 91 Allante has an amp in each speaker enclosure. 4 total. Had to replace 2 amps in mine to stop the noise.