1999 9-3 Saab Problem

ok, need some major feedback back on this vehicle and situation from all you guys that know your stuff on Saab. it is a 1999 Saab 9-3 and i installed an old school Pioneer XM (GEX-FM903XM) unit into it on the 28th of March. everything worked coming in but the customer told me that the display above the radio didn't really fit in real tight after he had some other work done on the vehicle and proceeded to show me that he was using a folded piece of paper to hold this panel in. i didn't think much of it at the time but  i also noticed that the radio holes (just like Ford radios) showed evidence of someone pulling the radio out prior to me working on it. ok, on to the problem. i put the xm unit on the back of the passenger side seat in the hatchback area and ran all wiring (except ground - chassis ground) up to behind the radio on the passenger side. i soldered the constant and ignition wires from the xm onto the back of the radio and taped them off. ok, everything works fine and the unit picks up the channels and everything when i backed the vehicle out of the shop. then a week later he calls saying some of his lights (hvac/shifter/radio lighting) isn't working and wants to set up an appointment to have it checked out. i schedule the vehicle when i am working the next day and he is fine with that. then he doesn't show up for the appointment and comes in on my day off. the other installer in the shop calls me at home because he hasn't worked on Saab and to get some direction on where i ran all the wiring etc. i walk him thru a couple hours of troubleshooting to no avail. during the troubleshooting he mentions that the customer told him that a couple of days after the installation he noticed that some (but not all) of the lights on the dash, shifter, and radio were not working. he pushed on the face of the radio and all of them started working fine so he was fine. then he noticed the same thing happening randomly (same lights but just not out all of the time) and then finely only the radio display was fixed by pushing on the face of the radio. we checked all fuses and even cut the wires loose from the radio to see if something was feeding back thru the unit. nothing worked so i did a damage claim a couple of days later and listed it under "Needs further investigation" to determine if i was at fault or if this was just an unfortunate, ill-timed, isolated issue waiting to happen. so yesterday the insurance dept calls me needing details and tells me that the vehicle is getting checked at a Saab dealership to determine if we caused this problem or not. about an hour later the customer calls our store saying they gave him a $700 estimate to fix the vehicle. does this sound fishing to anyone else or is it possible that tapping the 2 wires behind the radio did this damage. i personally can't think of anything that could have happened to cause this and i am wondering if the dealership is just soaking us for insurance money. any and all help with this problem will be greatly appreciated since this could be my job or at least a stain on my reputation that will be placed on me unfairly. thanks again!

You typed that you cut the wires loose from the headunit and the problem remained.  I assume that's only the power wires to the XM unit.  If you're sure you used the right wires (not dimmer/ illumination wires), it sounds like the radio has an internal short that's causing problems.  Try another one and see if the problem goes away.