Just a small but annoying issue with my 1991 zed- my minidisc player glitches like mad when used in the car, even when the engine isn't running... but is usually worse when the engine is running... And its very intermittent and doesn't seem to be affected too much by temperature. But the strange thing is the unit works perfectly fine outside of the car, either hooked up to my lab power supply or directly off a 12v battery. I've opened up the head unit itself, cleaned all lenses, mechanical parts and closely inspected all capacitors and everything seems fine. What could possibly be causing this kind of electrical interference? I'm guessing unclean power? For example, it still has a series 1 PTU that everyone says I should replace as preventative maintenance, but no idea if at all relevant. Only other electrical mods are a Nistune ecu, auto to manual swap, turbosmart boost controller, radio frequency step up converter and a crappy compact kicker subwoofer (doesn't matter if connected or not) and faulty clock removed. Oh it also had a break (broken ignition power wire) in the main loom under the front right guard that I bypassed many years ago. Any ideas?